diff --git a/apps/daxpay-admin/src/api/payment/develop/develop-trade.api.ts b/apps/daxpay-admin/src/api/payment/develop/develop-trade.api.ts
index 66fce51a0..2064e07d5 100644
--- a/apps/daxpay-admin/src/api/payment/develop/develop-trade.api.ts
+++ b/apps/daxpay-admin/src/api/payment/develop/develop-trade.api.ts
@@ -82,6 +82,12 @@ export interface PayParam {
   notifyUrl?: string;
   /** 同步跳转地址 */
   returnUrl?: string;
+  /** 商户附加参数(回调原样返回) */
+  attach?: string;
+  /** 支付扩展参数(JSON, 通道长尾参数) */
+  extraParam?: string;
+  /** 限制支付类型(如 no_credit 禁信用卡) */
+  limitPay?: string[];
   /** 过期时间(北京时间 yyyy-MM-dd HH:mm:ss) */
   expiredTime?: string;
   /** 客户端 IP(可选, 未传时由 unipay 从 HTTP 请求提取) */
diff --git a/apps/daxpay-admin/src/locales/langs/en-US/payment/develop.json b/apps/daxpay-admin/src/locales/langs/en-US/payment/develop.json
index 9ea24cbba..2183278f4 100644
--- a/apps/daxpay-admin/src/locales/langs/en-US/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/en-US/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "Merchant Info",
       "param": "Payment Params",
       "order": "Order Info",
-      "preview": "Request Preview"
+      "advanced": "Advanced Params"
     },
     "mode": {
       "label": "Pay Mode",
@@ -69,11 +69,6 @@
       "routeDesc": "Resolve channel merchant and capability via the app's channel routing",
       "directDesc": "Directly specify channel merchant + capability; skip channel routing"
     },
-    "preview": {
-      "title": "Request JSON",
-      "signBtn": "Sign Preview",
-      "empty": "No data"
-    },
     "field": {
       "privateKey": "Merchant Private Key",
       "mchNo": "Merchant",
@@ -85,6 +80,10 @@
       "openId": "OpenID",
       "authCode": "Payment code",
       "notifyUrl": "Async Notify URL",
+      "returnUrl": "Sync Return URL",
+      "attach": "Attach",
+      "extraParam": "Extra Params",
+      "limitPay": "Limit Pay",
       "expiredTime": "Expire Time",
       "bizOrderNo": "Order No.",
       "amount": "Amount (Fen)",
@@ -97,6 +96,10 @@
       "openId": "Required for WeChat jsapi/mini",
       "authCode": "Required for barcode pay",
       "notifyUrl": "https://...",
+      "returnUrl": "https://...",
+      "attach": "Returned as-is in callback",
+      "extraParam": "JSON, channel-specific params",
+      "limitPay": "Select or input, e.g. no_credit",
       "expiredTime": "Default 30 minutes if empty",
       "title": "Test order",
       "description": "Enter payment description"
@@ -145,7 +148,8 @@
       "amount": "Please enter the amount",
       "method": "Please select a payment method",
       "channelMchNo": "Please select a channel merchant",
-      "capability": "Please select a capability"
+      "capability": "Please select a capability",
+      "extraParam": "Extra params must be valid JSON"
     },
     "msg": {
       "signSuccess": "Sign generated successfully",
@@ -232,7 +236,7 @@
       "mchApp": "Merchant",
       "order": "Order",
       "param": "Extra Parameters",
-      "preview": "Request Preview"
+      "advanced": "Advanced Params"
     },
     "gatewayType": {
       "label": "Gateway Type",
@@ -241,11 +245,6 @@
       "cashierDesc": "Generate a cashier landing page where users choose a payment method",
       "aggregateDesc": "Generate an aggregate QR link, one code for multiple payment methods"
     },
-    "preview": {
-      "title": "Request JSON",
-      "signBtn": "Generate Sign Preview",
-      "empty": "No data"
-    },
     "field": {
       "privateKey": "Merchant Private Key",
       "mchNo": "Merchant",
@@ -256,12 +255,16 @@
       "description": "Description",
       "notifyUrl": "Async Notify URL",
       "returnUrl": "Sync Return URL",
+      "attach": "Attach",
+      "extraParam": "Extra Params",
       "expiredTime": "Expire Time",
       "storeNo": "Store No."
     },
     "placeholder": {
       "notifyUrl": "https://...",
       "returnUrl": "https://...",
+      "attach": "Returned as-is in callback",
+      "extraParam": "JSON, channel-specific params",
       "expiredTime": "Default 30 min",
       "storeNo": "Offline store number",
       "title": "Test order",
@@ -304,7 +307,8 @@
       "bizOrderNo": "Please enter order no.",
       "title": "Please enter payment title",
       "amount": "Please enter amount",
-      "gatewayPayType": "Please select gateway type"
+      "gatewayPayType": "Please select gateway type",
+      "extraParam": "Extra params must be valid JSON"
     },
     "msg": {
       "signSuccess": "Sign generated",
diff --git a/apps/daxpay-admin/src/locales/langs/id-ID/payment/develop.json b/apps/daxpay-admin/src/locales/langs/id-ID/payment/develop.json
index 847c0141c..aefc5f28b 100644
--- a/apps/daxpay-admin/src/locales/langs/id-ID/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/id-ID/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "Info Pedagang",
       "param": "Parameter Pembayaran",
       "order": "Info Pemesanan",
-      "preview": "Minta Pratinjau"
+      "advanced": "Parameter Lanjutan"
     },
     "mode": {
       "label": "Modus Bayar",
@@ -69,11 +69,6 @@
       "routeDesc": "Selesaikan pedagang saluran dan kemampuan melalui perutean saluran aplikasi",
       "directDesc": "Diputuskan oleh pedagang saluran + kemampuan; lewati perutean saluran"
     },
-    "preview": {
-      "title": "Minta JSON",
-      "signBtn": "Pratinjau Tanda Tangan",
-      "empty": "Tidak ada data"
-    },
     "field": {
       "privateKey": "Kunci Pribadi Pedagang",
       "mchNo": "Pedagang",
@@ -89,7 +84,11 @@
       "bizOrderNo": "Nomor Pesanan.",
       "amount": "Jumlah (Fen)",
       "title": "Judul",
-      "description": "Keterangan"
+      "description": "Keterangan",
+      "returnUrl": "URL Return Sync",
+      "attach": "Lampiran Merchant",
+      "extraParam": "Parameter Ekstra",
+      "limitPay": "Batasan Pembayaran"
     },
     "placeholder": {
       "method": "Pilih metode pembayaran",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "Default 30 menit jika kosong",
       "title": "Urutan tes",
-      "description": "Masukkan deskripsi pembayaran"
+      "description": "Masukkan deskripsi pembayaran",
+      "returnUrl": "https://...",
+      "attach": "Dikembalikan apa adanya di callback",
+      "extraParam": "JSON, parameter khusus channel",
+      "limitPay": "Pilih atau input, mis. no_credit"
     },
     "default": {
       "titlePrefix": "Tes Bayar"
@@ -145,7 +148,8 @@
       "amount": "Silakan masukkan jumlahnya",
       "method": "Silakan pilih metode pembayaran",
       "channelMchNo": "Silakan pilih pedagang saluran",
-      "capability": "Silakan pilih kemampuan"
+      "capability": "Silakan pilih kemampuan",
+      "extraParam": "Parameter ekstra harus JSON valid"
     },
     "msg": {
       "signSuccess": "Tanda tangan berhasil dibuat",
@@ -232,7 +236,7 @@
       "mchApp": "Info Merchant",
       "order": "Info Pesanan",
       "param": "Parameter Tambahan",
-      "preview": "Pratinjau Permintaan"
+      "advanced": "Parameter Lanjutan"
     },
     "gatewayType": {
       "label": "Tipe Gateway",
@@ -241,11 +245,6 @@
       "cashierDesc": "Buat halaman kasir, pengguna memilih metode pembayaran",
       "aggregateDesc": "Buat tautan QR agregat, satu kode untuk banyak pembayaran"
     },
-    "preview": {
-      "title": "JSON Permintaan",
-      "signBtn": "Buat Pratinjau Tanda Tangan",
-      "empty": "Tidak ada data"
-    },
     "field": {
       "privateKey": "Kunci Pribadi Merchant",
       "mchNo": "Merchant",
@@ -257,7 +256,9 @@
       "notifyUrl": "URL Notifikasi Async",
       "returnUrl": "URL Return Sync",
       "expiredTime": "Waktu Kedaluwarsa",
-      "storeNo": "No. Toko"
+      "storeNo": "No. Toko",
+      "attach": "Lampiran Merchant",
+      "extraParam": "Parameter Ekstra"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "Default 30 mnt",
       "storeNo": "Nomor toko offline",
       "title": "Pesanan uji",
-      "description": "Masukkan deskripsi pembayaran"
+      "description": "Masukkan deskripsi pembayaran",
+      "attach": "Dikembalikan apa adanya di callback",
+      "extraParam": "JSON, parameter khusus channel"
     },
     "default": {
       "titlePrefix": "Tes Gateway Pay"
@@ -304,7 +307,8 @@
       "bizOrderNo": "Silakan masukkan no. pesanan",
       "title": "Silakan masukkan judul pembayaran",
       "amount": "Silakan masukkan jumlah",
-      "gatewayPayType": "Silakan pilih tipe gateway"
+      "gatewayPayType": "Silakan pilih tipe gateway",
+      "extraParam": "Parameter ekstra harus JSON valid"
     },
     "msg": {
       "signSuccess": "Tanda tangan dibuat",
diff --git a/apps/daxpay-admin/src/locales/langs/ja-JP/payment/develop.json b/apps/daxpay-admin/src/locales/langs/ja-JP/payment/develop.json
index 5ba199986..47f24bfb2 100644
--- a/apps/daxpay-admin/src/locales/langs/ja-JP/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/ja-JP/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "販売者情報",
       "param": "支払いパラメータ",
       "order": "注文情報",
-      "preview": "プレビューのリクエスト"
+      "advanced": "高度パラメータ"
     },
     "mode": {
       "label": "ペイモード",
@@ -69,11 +69,6 @@
       "routeDesc": "アプリのチャネルルーティングを介してチャネルマーチャントと機能を解決します",
       "directDesc": "チャネル販売業者と能力によって決定されます。チャンネルルーティングをスキップする"
     },
-    "preview": {
-      "title": "JSONをリクエストする",
-      "signBtn": "署名プレビュー",
-      "empty": "データなし"
-    },
     "field": {
       "privateKey": "販売者の秘密鍵",
       "mchNo": "商人",
@@ -89,7 +84,11 @@
       "bizOrderNo": "注文番号",
       "amount": "量（フェン）",
       "title": "タイトル",
-      "description": "説明"
+      "description": "説明",
+      "returnUrl": "同期リダイレクトURL",
+      "attach": "マーチャント添付パラメータ",
+      "extraParam": "拡張パラメータ",
+      "limitPay": "支払制限タイプ"
     },
     "placeholder": {
       "method": "支払い方法を選択してください",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "空の場合はデフォルトで 30 分",
       "title": "テストの順序",
-      "description": "支払いの説明を入力してください"
+      "description": "支払いの説明を入力してください",
+      "returnUrl": "https://...",
+      "attach": "コールバック時にそのまま返却",
+      "extraParam": "JSON形式, チャネル固有パラメータ",
+      "limitPay": "選択または入力（例: no_credit）"
     },
     "default": {
       "titlePrefix": "テストペイ"
@@ -145,7 +148,8 @@
       "amount": "金額を入力してください",
       "method": "お支払い方法を選択してください",
       "channelMchNo": "チャネル販売者を選択してください",
-      "capability": "機能を選択してください"
+      "capability": "機能を選択してください",
+      "extraParam": "拡張パラメータは有効なJSON形式である必要があります"
     },
     "msg": {
       "signSuccess": "署名は正常に生成されました",
@@ -232,7 +236,7 @@
       "mchApp": "マーチャント情報",
       "order": "注文情報",
       "param": "拡張パラメータ",
-      "preview": "リクエストプレビュー"
+      "advanced": "高度パラメータ"
     },
     "gatewayType": {
       "label": "ゲートウェイ種別",
@@ -241,11 +245,6 @@
       "cashierDesc": "レジランディングページを生成し、ユーザーが支払い方法を選択",
       "aggregateDesc": "集合QRリンクを生成し、一つのコードで複数支払いを自動識別"
     },
-    "preview": {
-      "title": "リクエストJSON",
-      "signBtn": "署名プレビュー生成",
-      "empty": "データなし"
-    },
     "field": {
       "privateKey": "マーチャント秘密鍵",
       "mchNo": "マーチャント",
@@ -257,7 +256,9 @@
       "notifyUrl": "非同期通知URL",
       "returnUrl": "同期リダイレクトURL",
       "expiredTime": "有効期限",
-      "storeNo": "店舗番号"
+      "storeNo": "店舗番号",
+      "attach": "マーチャント添付パラメータ",
+      "extraParam": "拡張パラメータ"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "空欄で30分",
       "storeNo": "オフライン店舗番号",
       "title": "テスト注文",
-      "description": "支払説明を入力"
+      "description": "支払説明を入力",
+      "attach": "コールバック時にそのまま返却",
+      "extraParam": "JSON形式, チャネル固有パラメータ"
     },
     "default": {
       "titlePrefix": "テストゲートウェイ決済"
@@ -304,7 +307,8 @@
       "bizOrderNo": "注文番号を入力してください",
       "title": "支払タイトルを入力してください",
       "amount": "支払金額を入力してください",
-      "gatewayPayType": "ゲートウェイ種別を選択してください"
+      "gatewayPayType": "ゲートウェイ種別を選択してください",
+      "extraParam": "拡張パラメータは有効なJSON形式である必要があります"
     },
     "msg": {
       "signSuccess": "署名を生成しました",
diff --git a/apps/daxpay-admin/src/locales/langs/ko-KR/payment/develop.json b/apps/daxpay-admin/src/locales/langs/ko-KR/payment/develop.json
index 12700fcbc..cbe243579 100644
--- a/apps/daxpay-admin/src/locales/langs/ko-KR/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/ko-KR/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "판매자 정보",
       "param": "결제 매개변수",
       "order": "주문 정보",
-      "preview": "미리보기 요청"
+      "advanced": "고급 매개변수"
     },
     "mode": {
       "label": "지불 모드",
@@ -69,11 +69,6 @@
       "routeDesc": "앱의 채널 라우팅을 통해 채널 판매자 및 기능을 해결합니다.",
       "directDesc": "채널 판매자 + 역량에 따라 결정됩니다. 채널 라우팅 건너뛰기"
     },
-    "preview": {
-      "title": "JSON 요청",
-      "signBtn": "서명 미리보기",
-      "empty": "데이터 없음"
-    },
     "field": {
       "privateKey": "판매자 개인 키",
       "mchNo": "상인",
@@ -89,7 +84,11 @@
       "bizOrderNo": "주문번호",
       "amount": "금액(펜)",
       "title": "제목",
-      "description": "설명"
+      "description": "설명",
+      "returnUrl": "동기 리다이렉트 URL",
+      "attach": "가맹점 추가 매개변수",
+      "extraParam": "확장 매개변수",
+      "limitPay": "결제 제한 유형"
     },
     "placeholder": {
       "method": "결제 수단 선택",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "비어 있는 경우 기본값은 30분입니다.",
       "title": "테스트 순서",
-      "description": "결제 설명 입력"
+      "description": "결제 설명 입력",
+      "returnUrl": "https://...",
+      "attach": "콜백 시 그대로 반환",
+      "extraParam": "JSON, 채널 고유 매개변수",
+      "limitPay": "선택 또는 입력, 예: no_credit"
     },
     "default": {
       "titlePrefix": "테스트 페이"
@@ -145,7 +148,8 @@
       "amount": "금액을 입력해주세요.",
       "method": "결제수단을 선택해주세요",
       "channelMchNo": "채널 판매자를 선택하세요.",
-      "capability": "기능을 선택해 주세요"
+      "capability": "기능을 선택해 주세요",
+      "extraParam": "확장 매개변수는 유효한 JSON 형식이어야 합니다"
     },
     "msg": {
       "signSuccess": "서명이 성공적으로 생성되었습니다.",
@@ -232,7 +236,7 @@
       "mchApp": "가맹점 정보",
       "order": "주문 정보",
       "param": "확장 매개변수",
-      "preview": "요청 미리보기"
+      "advanced": "고급 매개변수"
     },
     "gatewayType": {
       "label": "게이트웨이 유형",
@@ -241,11 +245,6 @@
       "cashierDesc": "캐시어 랜딩 페이지 생성, 사용자가 결제 방법 선택",
       "aggregateDesc": "통합 QR 링크 생성, 하나의 코드로 다중 결제 자동 식별"
     },
-    "preview": {
-      "title": "요청 JSON",
-      "signBtn": "서명 미리보기 생성",
-      "empty": "데이터 없음"
-    },
     "field": {
       "privateKey": "가맹점 개인키",
       "mchNo": "가맹점",
@@ -257,7 +256,9 @@
       "notifyUrl": "비동기 알림 URL",
       "returnUrl": "동기 리다이렉트 URL",
       "expiredTime": "만료 시간",
-      "storeNo": "매장 번호"
+      "storeNo": "매장 번호",
+      "attach": "가맹점 추가 매개변수",
+      "extraParam": "확장 매개변수"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "비워두면 30분",
       "storeNo": "오프라인 매장 번호",
       "title": "테스트 주문",
-      "description": "결제 설명 입력"
+      "description": "결제 설명 입력",
+      "attach": "콜백 시 그대로 반환",
+      "extraParam": "JSON, 채널 고유 매개변수"
     },
     "default": {
       "titlePrefix": "테스트 게이트웨이 결제"
@@ -304,7 +307,8 @@
       "bizOrderNo": "주문번호를 입력해 주세요",
       "title": "결제 제목을 입력해 주세요",
       "amount": "결제 금액을 입력해 주세요",
-      "gatewayPayType": "게이트웨이 유형을 선택해 주세요"
+      "gatewayPayType": "게이트웨이 유형을 선택해 주세요",
+      "extraParam": "확장 매개변수는 유효한 JSON 형식이어야 합니다"
     },
     "msg": {
       "signSuccess": "서명이 생성되었습니다",
diff --git a/apps/daxpay-admin/src/locales/langs/ms-MY/payment/develop.json b/apps/daxpay-admin/src/locales/langs/ms-MY/payment/develop.json
index a557869da..69eeb792c 100644
--- a/apps/daxpay-admin/src/locales/langs/ms-MY/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/ms-MY/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "Maklumat Peniaga",
       "param": "Param Pembayaran",
       "order": "Maklumat Pesanan",
-      "preview": "Minta Pratonton"
+      "advanced": "Parameter Lanjutan"
     },
     "mode": {
       "label": "Mod Bayar",
@@ -69,11 +69,6 @@
       "routeDesc": "Selesaikan pedagang saluran dan keupayaan melalui penghalaan saluran apl",
       "directDesc": "Diputuskan oleh pedagang saluran + keupayaan; langkau penghalaan saluran"
     },
-    "preview": {
-      "title": "Minta JSON",
-      "signBtn": "Pratonton Tandatangan",
-      "empty": "Tiada data"
-    },
     "field": {
       "privateKey": "Kunci Peribadi Pedagang",
       "mchNo": "saudagar",
@@ -89,7 +84,11 @@
       "bizOrderNo": "Pesanan No.",
       "amount": "Jumlah (Fen)",
       "title": "Tajuk",
-      "description": "Penerangan"
+      "description": "Penerangan",
+      "returnUrl": "URL Pulang Sync",
+      "attach": "Lampiran Pedagang",
+      "extraParam": "Parameter Ekstra",
+      "limitPay": "Had Pembayaran"
     },
     "placeholder": {
       "method": "Pilih kaedah pembayaran",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "Lalai 30 minit jika kosong",
       "title": "Perintah ujian",
-      "description": "Masukkan perihalan pembayaran"
+      "description": "Masukkan perihalan pembayaran",
+      "returnUrl": "https://...",
+      "attach": "Dipulangkan seperti asal",
+      "extraParam": "JSON, parameter khusus saluran",
+      "limitPay": "Pilih atau input, cth: no_credit"
     },
     "default": {
       "titlePrefix": "Uji Bayar"
@@ -145,7 +148,8 @@
       "amount": "Sila masukkan jumlah",
       "method": "Sila pilih kaedah pembayaran",
       "channelMchNo": "Sila pilih pedagang saluran",
-      "capability": "Sila pilih keupayaan"
+      "capability": "Sila pilih keupayaan",
+      "extraParam": "Parameter ekstra mesti JSON sah"
     },
     "msg": {
       "signSuccess": "Tanda berjaya dijana",
@@ -232,7 +236,7 @@
       "mchApp": "Maklumat Merchant",
       "order": "Maklumat Pesanan",
       "param": "Parameter Tambahan",
-      "preview": "Pratonton Permintaan"
+      "advanced": "Parameter Lanjutan"
     },
     "gatewayType": {
       "label": "Jenis Gateway",
@@ -241,11 +245,6 @@
       "cashierDesc": "Jana halaman pendarat juruwang, pengguna memilih kaedah pembayaran",
       "aggregateDesc": "Jana pautan QR agregat, satu kod untuk pelbagai pembayaran"
     },
-    "preview": {
-      "title": "JSON Permintaan",
-      "signBtn": "Jana Pratonton Tandatangan",
-      "empty": "Tiada data"
-    },
     "field": {
       "privateKey": "Kunci Peribadi Merchant",
       "mchNo": "Merchant",
@@ -257,7 +256,9 @@
       "notifyUrl": "URL Pemberitahuan Async",
       "returnUrl": "URL Pulang Sync",
       "expiredTime": "Masa Tamat",
-      "storeNo": "No. Kedai"
+      "storeNo": "No. Kedai",
+      "attach": "Lampiran Pedagang",
+      "extraParam": "Parameter Ekstra"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "Lalai 30 min",
       "storeNo": "Nombor kedai luar talian",
       "title": "Pesanan ujian",
-      "description": "Masukkan penerangan pembayaran"
+      "description": "Masukkan penerangan pembayaran",
+      "attach": "Dipulangkan seperti asal",
+      "extraParam": "JSON, parameter khusus saluran"
     },
     "default": {
       "titlePrefix": "Uji Gateway Pay"
@@ -304,7 +307,8 @@
       "bizOrderNo": "Sila masukkan no. pesanan",
       "title": "Sila masukkan tajuk pembayaran",
       "amount": "Sila masukkan jumlah",
-      "gatewayPayType": "Sila pilih jenis gateway"
+      "gatewayPayType": "Sila pilih jenis gateway",
+      "extraParam": "Parameter ekstra mesti JSON sah"
     },
     "msg": {
       "signSuccess": "Tandatangan dijana",
diff --git a/apps/daxpay-admin/src/locales/langs/th-TH/payment/develop.json b/apps/daxpay-admin/src/locales/langs/th-TH/payment/develop.json
index e9daf7c9e..fd6bf11d9 100644
--- a/apps/daxpay-admin/src/locales/langs/th-TH/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/th-TH/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "ข้อมูลผู้ขาย",
       "param": "พารามิเตอร์การชำระเงิน",
       "order": "ข้อมูลการสั่งซื้อ",
-      "preview": "ขอดูตัวอย่าง"
+      "advanced": "พารามิเตอร์ขั้นสูง"
     },
     "mode": {
       "label": "โหมดการชำระเงิน",
@@ -69,11 +69,6 @@
       "routeDesc": "แก้ไขผู้ค้าช่องทางและความสามารถผ่านการกำหนดเส้นทางช่องทางของแอป",
       "directDesc": "ตัดสินใจโดยช่องทางการค้า + ความสามารถ; ข้ามการกำหนดเส้นทางช่อง"
     },
-    "preview": {
-      "title": "ขอ JSON",
-      "signBtn": "ลงชื่อแสดงตัวอย่าง",
-      "empty": "ไม่มีข้อมูล"
-    },
     "field": {
       "privateKey": "รหัสส่วนตัวของผู้ขาย",
       "mchNo": "พ่อค้า",
@@ -89,7 +84,11 @@
       "bizOrderNo": "หมายเลขคำสั่งซื้อ",
       "amount": "จำนวนเงิน (เฟิน)",
       "title": "ชื่อ",
-      "description": "คำอธิบาย"
+      "description": "คำอธิบาย",
+      "returnUrl": "URL กลับพร้อมกัน",
+      "attach": "พารามิเตอร์แนบท้าย",
+      "extraParam": "พารามิเตอร์เพิ่มเติม",
+      "limitPay": "จำกัดประเภทการชำระ"
     },
     "placeholder": {
       "method": "เลือกวิธีการชำระเงิน",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "ค่าเริ่มต้น 30 นาทีหากว่างเปล่า",
       "title": "คำสั่งทดสอบ",
-      "description": "ป้อนคำอธิบายการชำระเงิน"
+      "description": "ป้อนคำอธิบายการชำระเงิน",
+      "returnUrl": "https://...",
+      "attach": "ส่งกลับตามเดิมเมื่อเรียกกลับ",
+      "extraParam": "JSON, พารามิเตอร์เฉพาะช่องทาง",
+      "limitPay": "เลือกหรือกรอก เช่น no_credit"
     },
     "default": {
       "titlePrefix": "ทดสอบการจ่าย"
@@ -145,7 +148,8 @@
       "amount": "กรุณากรอกจำนวนเงิน",
       "method": "กรุณาเลือกวิธีการชำระเงิน",
       "channelMchNo": "กรุณาเลือกช่องทางร้านค้า",
-      "capability": "โปรดเลือกความสามารถ"
+      "capability": "โปรดเลือกความสามารถ",
+      "extraParam": "พารามิเตอร์เพิ่มเติมต้องเป็น JSON ที่ถูกต้อง"
     },
     "msg": {
       "signSuccess": "สร้างเครื่องหมายสำเร็จแล้ว",
@@ -232,7 +236,7 @@
       "mchApp": "ข้อมูลร้านค้า",
       "order": "ข้อมูลคำสั่ง",
       "param": "พารามิเตอร์เพิ่มเติม",
-      "preview": "ดูตัวอย่างคำขอ"
+      "advanced": "พารามิเตอร์ขั้นสูง"
     },
     "gatewayType": {
       "label": "ประเภทเกตเวย์",
@@ -241,11 +245,6 @@
       "cashierDesc": "สร้างหน้าเคาเตอร์ ผู้ใช้เลือกวิธีการชำระเงิน",
       "aggregateDesc": "สร้างลิงก์ QR รวม หนึ่งรหัสสำหรับหลายวิธีการชำระเงิน"
     },
-    "preview": {
-      "title": "JSON คำขอ",
-      "signBtn": "สร้างตัวอย่างลายเซ็น",
-      "empty": "ไม่มีข้อมูล"
-    },
     "field": {
       "privateKey": "คีย์ส่วนตัวร้านค้า",
       "mchNo": "ร้านค้า",
@@ -257,7 +256,9 @@
       "notifyUrl": "URL แจ้งเตือน async",
       "returnUrl": "URL กลับ sync",
       "expiredTime": "เวลาหมดอายุ",
-      "storeNo": "เลขที่ร้าน"
+      "storeNo": "เลขที่ร้าน",
+      "attach": "พารามิเตอร์แนบท้าย",
+      "extraParam": "พารามิเตอร์เพิ่มเติม"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "ค่าเริ่มต้น 30 นาที",
       "storeNo": "เลขที่ร้านออฟไลน์",
       "title": "คำสั่งทดสอบ",
-      "description": "ป้อนคำอธิบายการชำระเงิน"
+      "description": "ป้อนคำอธิบายการชำระเงิน",
+      "attach": "ส่งกลับตามเดิมเมื่อเรียกกลับ",
+      "extraParam": "JSON, พารามิเตอร์เฉพาะช่องทาง"
     },
     "default": {
       "titlePrefix": "ทดสอบเกตเวย์"
@@ -304,7 +307,8 @@
       "bizOrderNo": "กรุณาป้อนเลขที่คำสั่ง",
       "title": "กรุณาป้อนชื่อการชำระเงิน",
       "amount": "กรุณาป้อนจำนวนเงิน",
-      "gatewayPayType": "กรุณาเลือกประเภทเกตเวย์"
+      "gatewayPayType": "กรุณาเลือกประเภทเกตเวย์",
+      "extraParam": "พารามิเตอร์เพิ่มเติมต้องเป็น JSON ที่ถูกต้อง"
     },
     "msg": {
       "signSuccess": "สร้างลายเซ็นแล้ว",
diff --git a/apps/daxpay-admin/src/locales/langs/vi-VN/payment/develop.json b/apps/daxpay-admin/src/locales/langs/vi-VN/payment/develop.json
index 2cb3a0aef..70e444da6 100644
--- a/apps/daxpay-admin/src/locales/langs/vi-VN/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/vi-VN/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "Thông tin người bán",
       "param": "Thông số thanh toán",
       "order": "Thông tin đặt hàng",
-      "preview": "Yêu cầu xem trước"
+      "advanced": "Tham số nâng cao"
     },
     "mode": {
       "label": "Chế độ thanh toán",
@@ -69,11 +69,6 @@
       "routeDesc": "Giải quyết khả năng và người bán kênh thông qua định tuyến kênh của ứng dụng",
       "directDesc": "Quyết định bởi người bán kênh + khả năng; bỏ qua định tuyến kênh"
     },
-    "preview": {
-      "title": "Yêu cầu JSON",
-      "signBtn": "Xem trước ký hiệu",
-      "empty": "Không có dữ liệu"
-    },
     "field": {
       "privateKey": "Khóa riêng của người bán",
       "mchNo": "Thương gia",
@@ -89,7 +84,11 @@
       "bizOrderNo": "Số thứ tự",
       "amount": "Số tiền (Fen)",
       "title": "Tiêu đề",
-      "description": "Sự miêu tả"
+      "description": "Sự miêu tả",
+      "returnUrl": "URL trả về đồng bộ",
+      "attach": "Tham số đính kèm",
+      "extraParam": "Tham số mở rộng",
+      "limitPay": "Giới hạn thanh toán"
     },
     "placeholder": {
       "method": "Chọn phương thức thanh toán",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "Mặc định 30 phút nếu trống",
       "title": "Thứ tự kiểm tra",
-      "description": "Nhập mô tả thanh toán"
+      "description": "Nhập mô tả thanh toán",
+      "returnUrl": "https://...",
+      "attach": "Trả nguyên dạng khi callback",
+      "extraParam": "JSON, tham số riêng của kênh",
+      "limitPay": "Chọn hoặc nhập, vd: no_credit"
     },
     "default": {
       "titlePrefix": "Trả tiền thử nghiệm"
@@ -145,7 +148,8 @@
       "amount": "Vui lòng nhập số tiền",
       "method": "Vui lòng chọn phương thức thanh toán",
       "channelMchNo": "Vui lòng chọn một người bán kênh",
-      "capability": "Vui lòng chọn một khả năng"
+      "capability": "Vui lòng chọn một khả năng",
+      "extraParam": "Tham số mở rộng phải là JSON hợp lệ"
     },
     "msg": {
       "signSuccess": "Đăng ký được tạo thành công",
@@ -232,7 +236,7 @@
       "mchApp": "Thông tin merchant",
       "order": "Thông tin đơn hàng",
       "param": "Tham số mở rộng",
-      "preview": "Xem trước yêu cầu"
+      "advanced": "Tham số nâng cao"
     },
     "gatewayType": {
       "label": "Loại cổng",
@@ -241,11 +245,6 @@
       "cashierDesc": "Tạo trang đích quầy thu ngân, người dùng chọn phương thức thanh toán",
       "aggregateDesc": "Tạo liên kết QR tổng hợp, một mã cho nhiều phương thức thanh toán"
     },
-    "preview": {
-      "title": "JSON yêu cầu",
-      "signBtn": "Tạo xem trước chữ ký",
-      "empty": "Không có dữ liệu"
-    },
     "field": {
       "privateKey": "Khóa riêng merchant",
       "mchNo": "Merchant",
@@ -257,7 +256,9 @@
       "notifyUrl": "URL thông báo bất đồng bộ",
       "returnUrl": "URL trả về đồng bộ",
       "expiredTime": "Thời gian hết hạn",
-      "storeNo": "Số cửa hàng"
+      "storeNo": "Số cửa hàng",
+      "attach": "Tham số đính kèm",
+      "extraParam": "Tham số mở rộng"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "Mặc định 30 phút",
       "storeNo": "Số cửa hàng ngoại tuyến",
       "title": "Đơn hàng thử nghiệm",
-      "description": "Nhập mô tả thanh toán"
+      "description": "Nhập mô tả thanh toán",
+      "attach": "Trả nguyên dạng khi callback",
+      "extraParam": "JSON, tham số riêng của kênh"
     },
     "default": {
       "titlePrefix": "Test cổng thanh toán"
@@ -304,7 +307,8 @@
       "bizOrderNo": "Vui lòng nhập số đơn hàng",
       "title": "Vui lòng nhập tiêu đề thanh toán",
       "amount": "Vui lòng nhập số tiền",
-      "gatewayPayType": "Vui lòng chọn loại cổng"
+      "gatewayPayType": "Vui lòng chọn loại cổng",
+      "extraParam": "Tham số mở rộng phải là JSON hợp lệ"
     },
     "msg": {
       "signSuccess": "Đã tạo chữ ký",
diff --git a/apps/daxpay-admin/src/locales/langs/zh-CN/payment/develop.json b/apps/daxpay-admin/src/locales/langs/zh-CN/payment/develop.json
index d8ed51e8c..699fc7ef9 100644
--- a/apps/daxpay-admin/src/locales/langs/zh-CN/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/zh-CN/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "商户信息",
       "param": "支付参数",
       "order": "订单信息",
-      "preview": "请求预览"
+      "advanced": "高级参数"
     },
     "mode": {
       "label": "支付模式",
@@ -69,11 +69,6 @@
       "routeDesc": "按应用通道路由解析通道商户与支付能力",
       "directDesc": "由通道商户+支付能力直接决定支付实现，跳过通道路由"
     },
-    "preview": {
-      "title": "请求参数 JSON",
-      "signBtn": "生成签名预览",
-      "empty": "暂无数据"
-    },
     "field": {
       "privateKey": "商户私钥",
       "mchNo": "商户",
@@ -85,6 +80,10 @@
       "openId": "OpenID",
       "authCode": "付款码",
       "notifyUrl": "异步通知地址",
+      "returnUrl": "同步跳转地址",
+      "attach": "商户附加参数",
+      "extraParam": "支付扩展参数",
+      "limitPay": "限制支付类型",
       "expiredTime": "支付超时时间",
       "bizOrderNo": "订单号",
       "amount": "支付金额(分)",
@@ -97,6 +96,10 @@
       "openId": "微信 jsapi/mini 场景必填",
       "authCode": "付款码支付必填",
       "notifyUrl": "https://...",
+      "returnUrl": "https://...",
+      "attach": "回调时原样返回",
+      "extraParam": "JSON 格式, 通道特有长尾参数",
+      "limitPay": "选择或输入限制项, 如 no_credit",
       "expiredTime": "留空默认 30 分钟",
       "title": "测试订单",
       "description": "请输入支付描述"
@@ -145,7 +148,8 @@
       "amount": "请输入支付金额",
       "method": "请选择支付方式",
       "channelMchNo": "请选择通道商户",
-      "capability": "请选择支付能力"
+      "capability": "请选择支付能力",
+      "extraParam": "扩展参数需为合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "签名生成成功",
@@ -232,7 +236,7 @@
       "mchApp": "商户信息",
       "order": "订单信息",
       "param": "扩展参数",
-      "preview": "请求预览"
+      "advanced": "高级参数"
     },
     "gatewayType": {
       "label": "网关支付类型",
@@ -241,11 +245,6 @@
       "cashierDesc": "生成收银台落地页，用户在页面选择支付方式",
       "aggregateDesc": "生成聚合扫码链接，一码多付自动识别"
     },
-    "preview": {
-      "title": "请求参数 JSON",
-      "signBtn": "生成签名预览",
-      "empty": "暂无数据"
-    },
     "field": {
       "privateKey": "商户私钥",
       "mchNo": "商户",
@@ -256,12 +255,16 @@
       "description": "支付描述",
       "notifyUrl": "异步通知地址",
       "returnUrl": "同步跳转地址",
+      "attach": "商户附加参数",
+      "extraParam": "支付扩展参数",
       "expiredTime": "支付超时时间",
       "storeNo": "门店号"
     },
     "placeholder": {
       "notifyUrl": "https://...",
       "returnUrl": "https://...",
+      "attach": "回调时原样返回",
+      "extraParam": "JSON 格式, 通道特有长尾参数",
       "expiredTime": "留空默认 30 分钟",
       "storeNo": "线下经营门店号",
       "title": "测试订单",
@@ -304,7 +307,8 @@
       "bizOrderNo": "请输入订单号",
       "title": "请输入支付标题",
       "amount": "请输入支付金额",
-      "gatewayPayType": "请选择网关支付类型"
+      "gatewayPayType": "请选择网关支付类型",
+      "extraParam": "扩展参数需为合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "签名生成成功",
diff --git a/apps/daxpay-admin/src/locales/langs/zh-HK/payment/develop.json b/apps/daxpay-admin/src/locales/langs/zh-HK/payment/develop.json
index 4cddfa967..4665dcfa5 100644
--- a/apps/daxpay-admin/src/locales/langs/zh-HK/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/zh-HK/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "商户信息",
       "param": "支付參數",
       "order": "訂單信息",
-      "preview": "請求預覽"
+      "advanced": "進階參數"
     },
     "mode": {
       "label": "支付模式",
@@ -69,11 +69,6 @@
       "routeDesc": "按應用通道路由解析通道商户與支付能力",
       "directDesc": "由通道商户+支付能力直接決定支付實現，跳過通道路由"
     },
-    "preview": {
-      "title": "請求參數 JSON",
-      "signBtn": "生成簽名預覽",
-      "empty": "暫無數據"
-    },
     "field": {
       "privateKey": "商户私鑰",
       "mchNo": "商户",
@@ -89,7 +84,11 @@
       "bizOrderNo": "訂單號",
       "amount": "支付金額(分)",
       "title": "支付標題",
-      "description": "支付描述"
+      "description": "支付描述",
+      "returnUrl": "同步跳轉地址",
+      "attach": "商戶附加參數",
+      "extraParam": "支付擴展參數",
+      "limitPay": "限制支付類型"
     },
     "placeholder": {
       "method": "請選擇支付方式",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "留空默認 30 分鐘",
       "title": "測試訂單",
-      "description": "請輸入支付描述"
+      "description": "請輸入支付描述",
+      "returnUrl": "https://...",
+      "attach": "回呼時原樣返回",
+      "extraParam": "JSON 格式, 通道特有長尾參數",
+      "limitPay": "選擇或輸入限制項, 如 no_credit"
     },
     "default": {
       "titlePrefix": "測試支付"
@@ -145,7 +148,8 @@
       "amount": "請輸入支付金額",
       "method": "請選擇支付方式",
       "channelMchNo": "請選擇通道商户",
-      "capability": "請選擇支付能力"
+      "capability": "請選擇支付能力",
+      "extraParam": "擴展參數需為合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "簽名生成成功",
@@ -232,7 +236,7 @@
       "mchApp": "商戶資訊",
       "order": "訂單資訊",
       "param": "擴展參數",
-      "preview": "請求預覽"
+      "advanced": "進階參數"
     },
     "gatewayType": {
       "label": "網關支付類型",
@@ -241,11 +245,6 @@
       "cashierDesc": "生成收銀台落地頁，用戶喺頁面選擇支付方式",
       "aggregateDesc": "生成聚合掃碼連結，一碼多付自動識別"
     },
-    "preview": {
-      "title": "請求參數 JSON",
-      "signBtn": "生成簽名預覽",
-      "empty": "暫無數據"
-    },
     "field": {
       "privateKey": "商戶私鑰",
       "mchNo": "商戶",
@@ -257,7 +256,9 @@
       "notifyUrl": "異步通知地址",
       "returnUrl": "同步跳轉地址",
       "expiredTime": "支付超時時間",
-      "storeNo": "門店號"
+      "storeNo": "門店號",
+      "attach": "商戶附加參數",
+      "extraParam": "支付擴展參數"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "留空預設 30 分鐘",
       "storeNo": "線下經營門店號",
       "title": "測試訂單",
-      "description": "請輸入支付描述"
+      "description": "請輸入支付描述",
+      "attach": "回呼時原樣返回",
+      "extraParam": "JSON 格式, 通道特有長尾參數"
     },
     "default": {
       "titlePrefix": "測試網關支付"
@@ -304,7 +307,8 @@
       "bizOrderNo": "請輸入訂單號",
       "title": "請輸入支付標題",
       "amount": "請輸入支付金額",
-      "gatewayPayType": "請選擇網關支付類型"
+      "gatewayPayType": "請選擇網關支付類型",
+      "extraParam": "擴展參數需為合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "簽名生成成功",
diff --git a/apps/daxpay-admin/src/locales/langs/zh-TW/payment/develop.json b/apps/daxpay-admin/src/locales/langs/zh-TW/payment/develop.json
index 1d110ccb1..5ebc6f688 100644
--- a/apps/daxpay-admin/src/locales/langs/zh-TW/payment/develop.json
+++ b/apps/daxpay-admin/src/locales/langs/zh-TW/payment/develop.json
@@ -60,7 +60,7 @@
       "mchApp": "商戶資訊",
       "param": "支付引數",
       "order": "訂單資訊",
-      "preview": "請求預覽"
+      "advanced": "進階參數"
     },
     "mode": {
       "label": "支付模式",
@@ -69,11 +69,6 @@
       "routeDesc": "按應用通道路由解析通道商戶與支付能力",
       "directDesc": "由通道商戶+支付能力直接決定支付實現，跳過通道路由"
     },
-    "preview": {
-      "title": "請求引數 JSON",
-      "signBtn": "生成簽名預覽",
-      "empty": "暫無資料"
-    },
     "field": {
       "privateKey": "商戶私鑰",
       "mchNo": "商戶",
@@ -89,7 +84,11 @@
       "bizOrderNo": "訂單號",
       "amount": "支付金額(分)",
       "title": "支付標題",
-      "description": "支付描述"
+      "description": "支付描述",
+      "returnUrl": "同步跳轉地址",
+      "attach": "商戶附加參數",
+      "extraParam": "支付擴充參數",
+      "limitPay": "限制支付類型"
     },
     "placeholder": {
       "method": "請選擇支付方式",
@@ -99,7 +98,11 @@
       "notifyUrl": "https://...",
       "expiredTime": "留空預設 30 分鐘",
       "title": "測試訂單",
-      "description": "請輸入支付描述"
+      "description": "請輸入支付描述",
+      "returnUrl": "https://...",
+      "attach": "回呼時原樣返回",
+      "extraParam": "JSON 格式, 通道特有長尾參數",
+      "limitPay": "選擇或輸入限制項, 如 no_credit"
     },
     "default": {
       "titlePrefix": "測試支付"
@@ -145,7 +148,8 @@
       "amount": "請輸入支付金額",
       "method": "請選擇支付方式",
       "channelMchNo": "請選擇通道商戶",
-      "capability": "請選擇支付能力"
+      "capability": "請選擇支付能力",
+      "extraParam": "擴充參數需為合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "簽名生成成功",
@@ -232,7 +236,7 @@
       "mchApp": "商戶資訊",
       "order": "訂單資訊",
       "param": "擴充參數",
-      "preview": "請求預覽"
+      "advanced": "進階參數"
     },
     "gatewayType": {
       "label": "網關支付類型",
@@ -241,11 +245,6 @@
       "cashierDesc": "產生收銀台落地頁，使用者在頁面選擇支付方式",
       "aggregateDesc": "產生聚合掃碼連結，一碼多付自動識別"
     },
-    "preview": {
-      "title": "請求參數 JSON",
-      "signBtn": "產生簽名預覽",
-      "empty": "暫無資料"
-    },
     "field": {
       "privateKey": "商戶私鑰",
       "mchNo": "商戶",
@@ -257,7 +256,9 @@
       "notifyUrl": "非同步通知地址",
       "returnUrl": "同步跳轉地址",
       "expiredTime": "支付逾時時間",
-      "storeNo": "門店號"
+      "storeNo": "門店號",
+      "attach": "商戶附加參數",
+      "extraParam": "支付擴充參數"
     },
     "placeholder": {
       "notifyUrl": "https://...",
@@ -265,7 +266,9 @@
       "expiredTime": "留空預設 30 分鐘",
       "storeNo": "線下經營門店號",
       "title": "測試訂單",
-      "description": "請輸入支付描述"
+      "description": "請輸入支付描述",
+      "attach": "回呼時原樣返回",
+      "extraParam": "JSON 格式, 通道特有長尾參數"
     },
     "default": {
       "titlePrefix": "測試網關支付"
@@ -304,7 +307,8 @@
       "bizOrderNo": "請輸入訂單號",
       "title": "請輸入支付標題",
       "amount": "請輸入支付金額",
-      "gatewayPayType": "請選擇網關支付類型"
+      "gatewayPayType": "請選擇網關支付類型",
+      "extraParam": "擴充參數需為合法 JSON 格式"
     },
     "msg": {
       "signSuccess": "簽名產生成功",
diff --git a/apps/daxpay-admin/src/views/payment/develop/gateway/DevelopGateway.vue b/apps/daxpay-admin/src/views/payment/develop/gateway/DevelopGateway.vue
index 2508ed443..fa414104c 100644
--- a/apps/daxpay-admin/src/views/payment/develop/gateway/DevelopGateway.vue
+++ b/apps/daxpay-admin/src/views/payment/develop/gateway/DevelopGateway.vue
@@ -43,6 +43,21 @@
       amount: [{ required: true, message: $t('payment.develop.gateway.rule.amount') }],
       title: [{ required: true, message: $t('payment.develop.gateway.rule.title') }],
       gatewayPayType: [{ required: true, message: $t('payment.develop.gateway.rule.gatewayPayType') }],
+      // 扩展参数: 非空时校验 JSON 合法性
+      extraParam: [
+        {
+          validator: async (_rule: any, value: string) => {
+            if (value && value.trim()) {
+              try {
+                JSON.parse(value);
+              } catch {
+                throw new Error($t('payment.develop.gateway.rule.extraParam'));
+              }
+            }
+          },
+          trigger: 'blur',
+        },
+      ],
       // 私钥存独立 ref, 用自定义校验挂到 form 上
       privateKey: [
         {
@@ -65,8 +80,10 @@
     amount: 1,
     gatewayPayType: 'cashier',
     description: '',
+    // 高级参数(折叠面板中编辑, 默认空)
+    attach: '',
+    extraParam: '',
   });
-  const signPreviewLoading = ref(false);
 
   // ===== 下拉选项 =====
   const mchNoOptions = ref<LabelValue[]>([]);
@@ -84,12 +101,6 @@
       : $t('payment.develop.gateway.result.failModalTitle'),
   );
 
-  // ===== 签名预览(请求预览卡内联展示) =====
-  const signPreview = reactive({
-    signStr: '',
-    sign: '',
-  });
-
   /**
    * 生成商户订单号(时间戳 + 随机串)
    */
@@ -234,37 +245,6 @@
     return cleanPayload(payload);
   }
 
-  /** 当前请求 JSON 预览(剔除空值) */
-  const requestPreview = computed(() => {
-    return JSON.stringify(buildPayload(), null, 2);
-  });
-
-  /** 生成签名预览(内联展示, 不弹结果) */
-  async function handleSignPreview() {
-    // 重入守卫: :loading DOM 更新有 nextTick 延迟, 连点会绕过按钮 disabled
-    if (signPreviewLoading.value) {
-      return;
-    }
-    try {
-      await formRef.value?.validateFields(['privateKey']);
-    } catch {
-      // 校验失败: 表单已显示错误提示
-      return;
-    }
-    signPreviewLoading.value = true;
-    try {
-      const { data } = await DevelopGatewayApi.sign({
-        param: buildPayload(),
-        privateKey: privateKey.value,
-      });
-      signPreview.signStr = data?.signStr ?? '';
-      signPreview.sign = data?.sign ?? '';
-      message.success($t('payment.develop.gateway.msg.signSuccess'));
-    } finally {
-      signPreviewLoading.value = false;
-    }
-  }
-
   /** 复制文本到剪贴板 */
   async function copyText(text: string, successKey = 'payment.develop.gateway.msg.copySuccess') {
     if (!text) return;
@@ -309,8 +289,6 @@
         return;
       }
       payload.sign = signRes?.sign;
-      signPreview.signStr = signRes?.signStr ?? '';
-      signPreview.sign = signRes?.sign ?? '';
 
       // 直调网关预下单(无 Accesstoken, 完整商户契约)
       try {
@@ -344,12 +322,12 @@
       description: '',
       notifyUrl: undefined,
       returnUrl: undefined,
+      attach: undefined,
+      extraParam: undefined,
       expiredTime: undefined,
       storeNo: undefined,
     });
     mchAppOptions.value = [];
-    signPreview.signStr = '';
-    signPreview.sign = '';
     genBizOrderNo();
   }
 
@@ -485,14 +463,6 @@
                       />
                     </a-form-item>
                   </a-col>
-                  <a-col :span="24">
-                    <a-form-item :label="$t('payment.develop.gateway.field.returnUrl')" name="returnUrl">
-                      <a-input
-                        v-model:value="form.returnUrl"
-                        :placeholder="$t('payment.develop.gateway.placeholder.returnUrl')"
-                      />
-                    </a-form-item>
-                  </a-col>
                   <a-col :span="12">
                     <a-form-item :label="$t('payment.develop.gateway.field.expiredTime')" name="expiredTime">
                       <a-date-picker
@@ -579,64 +549,44 @@
                 </a-row>
               </a-card>
 
-              <!-- 卡4: 请求预览(实时 JSON + 签名预览) -->
-              <a-card class="rounded-xl shadow-sm">
-                <template #title>
-                  <div class="flex items-center gap-2">
-                    <IconifyIcon icon="ant-design:code-outlined" class="text-amber-500" />
-                    <span class="font-semibold">{{ $t('payment.develop.gateway.card.preview') }}</span>
-                  </div>
-                </template>
-                <template #extra>
-                  <a-button
-                    size="small"
-                    type="primary"
-                    :loading="signPreviewLoading"
-                    :disabled="signPreviewLoading"
-                    @click="handleSignPreview"
-                  >
-                    <template #icon><IconifyIcon icon="ant-design:safety-certificate-outlined" /></template>
-                    {{ $t('payment.develop.gateway.preview.signBtn') }}
-                  </a-button>
-                </template>
-
-                <!-- 实时请求 JSON -->
-                <div class="mb-3 text-xs font-medium text-muted-foreground">
-                  {{ $t('payment.develop.gateway.preview.title') }}
-                </div>
-                <pre class="code-box rounded-lg border border-border bg-muted/40 p-3 text-xs">{{ requestPreview }}</pre>
-
-                <!-- 签名预览结果 -->
-                <template v-if="signPreview.signStr || signPreview.sign">
-                  <a-divider class="!my-3" />
-                  <div class="preview-item mb-3">
-                    <div class="mb-1 flex items-center justify-between">
-                      <span class="text-xs font-medium text-foreground">
-                        {{ $t('payment.develop.sign.field.signStr') }}
-                      </span>
-                      <a-button size="small" type="link" @click="copyText(signPreview.signStr)">
-                        <IconifyIcon icon="ant-design:copy-outlined" />
-                      </a-button>
+              <!-- 卡4: 高级参数(折叠, 默认收起) -->
+              <a-collapse :default-active-key="[]" class="advanced-collapse">
+                <a-collapse-panel key="advanced">
+                  <template #header>
+                    <div class="flex items-center gap-2">
+                      <IconifyIcon icon="ant-design:setting-outlined" class="text-amber-500" />
+                      <span class="font-semibold">{{ $t('payment.develop.gateway.card.advanced') }}</span>
                     </div>
-                    <div class="code-box break-all rounded-lg border border-border bg-muted/40 p-3 text-xs">
-                      {{ signPreview.signStr || $t('payment.develop.gateway.preview.empty') }}
-                    </div>
-                  </div>
-                  <div class="preview-item">
-                    <div class="mb-1 flex items-center justify-between">
-                      <span class="text-xs font-medium text-foreground">
-                        {{ $t('payment.develop.sign.field.signValue') }}
-                      </span>
-                      <a-button size="small" type="link" @click="copyText(signPreview.sign)">
-                        <IconifyIcon icon="ant-design:copy-outlined" />
-                      </a-button>
-                    </div>
-                    <div class="code-box break-all rounded-lg border border-border bg-muted/40 p-3 text-xs">
-                      {{ signPreview.sign || $t('payment.develop.gateway.preview.empty') }}
-                    </div>
-                  </div>
-                </template>
-              </a-card>
+                  </template>
+                  <a-row :gutter="16">
+                    <a-col :span="24">
+                      <a-form-item :label="$t('payment.develop.gateway.field.returnUrl')" name="returnUrl">
+                        <a-input
+                          v-model:value="form.returnUrl"
+                          :placeholder="$t('payment.develop.gateway.placeholder.returnUrl')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                    <a-col :span="24">
+                      <a-form-item :label="$t('payment.develop.gateway.field.attach')" name="attach">
+                        <a-input
+                          v-model:value="form.attach"
+                          :placeholder="$t('payment.develop.gateway.placeholder.attach')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                    <a-col :span="24">
+                      <a-form-item :label="$t('payment.develop.gateway.field.extraParam')" name="extraParam">
+                        <a-textarea
+                          v-model:value="form.extraParam"
+                          :rows="3"
+                          :placeholder="$t('payment.develop.gateway.placeholder.extraParam')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                  </a-row>
+                </a-collapse-panel>
+              </a-collapse>
             </div>
           </a-col>
         </a-row>
@@ -789,6 +739,14 @@
       font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
     }
 
+    // 高级参数折叠面板: 视觉与 a-card 保持一致
+    .advanced-collapse {
+      border: 1px solid hsl(var(--border));
+      border-radius: 12px;
+      background-color: hsl(var(--card));
+      box-shadow: 0 1px 3px hsl(var(--foreground) / 0.04);
+    }
+
     // 底部悬浮居中胶囊栏: 固定在视口底部, 始终可点
     .action-bar {
       position: fixed;
diff --git a/apps/daxpay-admin/src/views/payment/develop/trade/DevelopTrade.vue b/apps/daxpay-admin/src/views/payment/develop/trade/DevelopTrade.vue
index 837006243..2f75a6f1b 100644
--- a/apps/daxpay-admin/src/views/payment/develop/trade/DevelopTrade.vue
+++ b/apps/daxpay-admin/src/views/payment/develop/trade/DevelopTrade.vue
@@ -48,6 +48,21 @@
       bizOrderNo: [{ required: true, message: $t('payment.develop.trade.rule.bizOrderNo') }],
       amount: [{ required: true, message: $t('payment.develop.trade.rule.amount') }],
       title: [{ required: true, message: $t('payment.develop.trade.rule.title') }],
+      // 扩展参数: 非空时校验 JSON 合法性
+      extraParam: [
+        {
+          validator: async (_rule: any, value: string) => {
+            if (value && value.trim()) {
+              try {
+                JSON.parse(value);
+              } catch {
+                throw new Error($t('payment.develop.trade.rule.extraParam'));
+              }
+            }
+          },
+          trigger: 'blur',
+        },
+      ],
       // 私钥存独立 ref, 用自定义校验挂到 form 上
       privateKey: [
         {
@@ -81,8 +96,14 @@
     method: '',
     capability: '',
     description: '',
+    // 高级参数(折叠面板中编辑, 默认空)
+    attach: '',
+    extraParam: '',
+    limitPay: [],
   });
-  const signPreviewLoading = ref(false);
+
+  // 限制支付类型候选(预置常用项, mode=tags 支持手输)
+  const limitPayOptions = [{ label: 'no_credit', value: 'no_credit' }];
 
   // ===== 下拉选项 =====
   const mchNoOptions = ref<LabelValue[]>([]);
@@ -114,12 +135,6 @@
     return { ...raw, resTime: formatted || raw.resTime };
   });
 
-  // ===== 签名预览(请求预览卡内联展示) =====
-  const signPreview = reactive({
-    signStr: '',
-    sign: '',
-  });
-
   /**
    * 生成商户订单号(时间戳 + 随机串)
    */
@@ -323,33 +338,6 @@
     return cleanPayload(payload);
   }
 
-  /** 当前请求 JSON 预览(剔除空值) */
-  const requestPreview = computed(() => {
-    return JSON.stringify(buildPayload(), null, 2);
-  });
-
-  /** 生成签名预览(内联展示, 不弹结果) */
-  async function handleSignPreview() {
-    try {
-      await formRef.value?.validateFields(['privateKey']);
-    } catch {
-      // 校验失败: 表单已显示错误提示
-      return;
-    }
-    signPreviewLoading.value = true;
-    try {
-      const { data } = await DevelopTradeApi.sign({
-        param: buildPayload(),
-        privateKey: privateKey.value,
-      });
-      signPreview.signStr = data?.signStr ?? '';
-      signPreview.sign = data?.sign ?? '';
-      message.success($t('payment.develop.trade.msg.signSuccess'));
-    } finally {
-      signPreviewLoading.value = false;
-    }
-  }
-
   /** 复制文本到剪贴板 */
   async function copyText(text: string, successKey = 'payment.develop.trade.msg.copySuccess') {
     if (!text) return;
@@ -384,8 +372,6 @@
         privateKey: privateKey.value,
       });
       payload.sign = signRes?.sign;
-      signPreview.signStr = signRes?.signStr ?? '';
-      signPreview.sign = signRes?.sign ?? '';
 
       // 直调统一支付(无 Accesstoken, 完整商户契约)
       // unipayPost 已将业务失败(code!=0)转为返回值, 仅网络层异常会 throw
@@ -424,14 +410,15 @@
       authCode: undefined,
       notifyUrl: undefined,
       returnUrl: undefined,
+      attach: undefined,
+      extraParam: undefined,
+      limitPay: undefined,
       expiredTime: undefined,
     });
     routeMode.value = 'route';
     mchAppOptions.value = [];
     channelMchNoOptions.value = [];
     capabilityOptions.value = [];
-    signPreview.signStr = '';
-    signPreview.sign = '';
     genBizOrderNo();
   }
 
@@ -705,58 +692,54 @@
                 </a-row>
               </a-card>
 
-              <!-- 卡4: 请求预览(实时 JSON + 签名预览) -->
-              <a-card class="rounded-xl shadow-sm">
-                <template #title>
-                  <div class="flex items-center gap-2">
-                    <IconifyIcon icon="ant-design:code-outlined" class="text-amber-500" />
-                    <span class="font-semibold">{{ $t('payment.develop.trade.card.preview') }}</span>
-                  </div>
-                </template>
-                <template #extra>
-                  <a-button size="small" type="primary" :loading="signPreviewLoading" @click="handleSignPreview">
-                    <template #icon><IconifyIcon icon="ant-design:safety-certificate-outlined" /></template>
-                    {{ $t('payment.develop.trade.preview.signBtn') }}
-                  </a-button>
-                </template>
-
-                <!-- 实时请求 JSON -->
-                <div class="mb-3 text-xs font-medium text-muted-foreground">
-                  {{ $t('payment.develop.trade.preview.title') }}
-                </div>
-                <pre class="code-box rounded-lg border border-border bg-muted/40 p-3 text-xs">{{ requestPreview }}</pre>
-
-                <!-- 签名预览结果 -->
-                <template v-if="signPreview.signStr || signPreview.sign">
-                  <a-divider class="!my-3" />
-                  <div class="preview-item mb-3">
-                    <div class="mb-1 flex items-center justify-between">
-                      <span class="text-xs font-medium text-foreground">
-                        {{ $t('payment.develop.sign.field.signStr') }}
-                      </span>
-                      <a-button size="small" type="link" @click="copyText(signPreview.signStr)">
-                        <IconifyIcon icon="ant-design:copy-outlined" />
-                      </a-button>
+              <!-- 卡4: 高级参数(折叠, 默认收起) -->
+              <a-collapse :default-active-key="[]" class="advanced-collapse">
+                <a-collapse-panel key="advanced">
+                  <template #header>
+                    <div class="flex items-center gap-2">
+                      <IconifyIcon icon="ant-design:setting-outlined" class="text-amber-500" />
+                      <span class="font-semibold">{{ $t('payment.develop.trade.card.advanced') }}</span>
                     </div>
-                    <div class="code-box break-all rounded-lg border border-border bg-muted/40 p-3 text-xs">
-                      {{ signPreview.signStr || $t('payment.develop.trade.preview.empty') }}
-                    </div>
-                  </div>
-                  <div class="preview-item">
-                    <div class="mb-1 flex items-center justify-between">
-                      <span class="text-xs font-medium text-foreground">
-                        {{ $t('payment.develop.sign.field.signValue') }}
-                      </span>
-                      <a-button size="small" type="link" @click="copyText(signPreview.sign)">
-                        <IconifyIcon icon="ant-design:copy-outlined" />
-                      </a-button>
-                    </div>
-                    <div class="code-box break-all rounded-lg border border-border bg-muted/40 p-3 text-xs">
-                      {{ signPreview.sign || $t('payment.develop.trade.preview.empty') }}
-                    </div>
-                  </div>
-                </template>
-              </a-card>
+                  </template>
+                  <a-row :gutter="16">
+                    <a-col :span="12">
+                      <a-form-item :label="$t('payment.develop.trade.field.returnUrl')" name="returnUrl">
+                        <a-input
+                          v-model:value="form.returnUrl"
+                          :placeholder="$t('payment.develop.trade.placeholder.returnUrl')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                    <a-col :span="12">
+                      <a-form-item :label="$t('payment.develop.trade.field.attach')" name="attach">
+                        <a-input
+                          v-model:value="form.attach"
+                          :placeholder="$t('payment.develop.trade.placeholder.attach')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                    <a-col :span="24">
+                      <a-form-item :label="$t('payment.develop.trade.field.limitPay')" name="limitPay">
+                        <a-select
+                          v-model:value="form.limitPay"
+                          mode="tags"
+                          :placeholder="$t('payment.develop.trade.placeholder.limitPay')"
+                          :options="limitPayOptions"
+                        />
+                      </a-form-item>
+                    </a-col>
+                    <a-col :span="24">
+                      <a-form-item :label="$t('payment.develop.trade.field.extraParam')" name="extraParam">
+                        <a-textarea
+                          v-model:value="form.extraParam"
+                          :rows="3"
+                          :placeholder="$t('payment.develop.trade.placeholder.extraParam')"
+                        />
+                      </a-form-item>
+                    </a-col>
+                  </a-row>
+                </a-collapse-panel>
+              </a-collapse>
             </div>
           </a-col>
         </a-row>
@@ -918,6 +901,14 @@
       font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
     }
 
+    // 高级参数折叠面板: 视觉与 a-card 保持一致
+    .advanced-collapse {
+      border: 1px solid hsl(var(--border));
+      border-radius: 12px;
+      background-color: hsl(var(--card));
+      box-shadow: 0 1px 3px hsl(var(--foreground) / 0.04);
+    }
+
     // 底部悬浮居中胶囊栏: 固定在视口底部, 始终可点
     .action-bar {
       position: fixed;