diff --git a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/controller/protocol/UserProtocolVersionController.java b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/controller/protocol/UserProtocolVersionController.java
index 8575c6c8b..d22c64c76 100644
--- a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/controller/protocol/UserProtocolVersionController.java
+++ b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/controller/protocol/UserProtocolVersionController.java
@@ -13,6 +13,7 @@ import cn.daxpay.open.platform.system.result.protocol.UserProtocolVersionResult;
 import cn.daxpay.open.platform.system.service.protocol.UserProtocolVersionService;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotNull;
 import lombok.RequiredArgsConstructor;
 import org.springframework.validation.annotation.Validated;
@@ -85,6 +86,20 @@ public class UserProtocolVersionController {
         return Res.ok(userProtocolVersionService.findById(id));
     }
 
+    /// 查询新建草稿可继承的源版本(同语言已发布优先, 否则最新归档)
+    ///
+    /// @param protocolId 协议ID
+    /// @param language 语言
+    /// @return 源版本, 无则 null
+    @PermCode(code = PermCodes.Action.VIEW)
+    @Operation(summary = "查询可继承源版本")
+    @GetMapping("/find-inherit-source")
+    public Result<UserProtocolVersionResult> findInheritSource(
+            @NotNull(message = "{validation.field.protocolId.notNull}") Long protocolId,
+            @NotBlank(message = "{validation.field.language.notBlank}") String language){
+        return Res.ok(userProtocolVersionService.findInheritSource(protocolId, language));
+    }
+
     /// 发布版本(草稿 -> 已发布, 同协议同语言原已发布自动归档)
     ///
     /// @param id 版本ID
diff --git a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/dao/protocol/UserProtocolVersionManager.java b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/dao/protocol/UserProtocolVersionManager.java
index 630ec247a..849334c64 100644
--- a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/dao/protocol/UserProtocolVersionManager.java
+++ b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/dao/protocol/UserProtocolVersionManager.java
@@ -40,6 +40,21 @@ public class UserProtocolVersionManager extends BaseManager<UserProtocolVersionM
                 .oneOpt();
     }
 
+    /// 查询可继承的源版本: 同协议同语言已发布优先, 否则取 versionNo 最大的归档版
+    public Optional<UserProtocolVersion> findLatestForInherit(Long protocolId, String language){
+        Optional<UserProtocolVersion> published = this.findPublished(protocolId, language);
+        if (published.isPresent()) {
+            return published;
+        }
+        return this.lambdaQuery()
+                .eq(UserProtocolVersion::getProtocolId, protocolId)
+                .eq(UserProtocolVersion::getLanguage, language)
+                .eq(UserProtocolVersion::getStatus, "ARCHIVED")
+                .orderByDesc(UserProtocolVersion::getVersionNo)
+                .last("LIMIT 1")
+                .oneOpt();
+    }
+
     /// 查询某协议下所有版本(级联删除/复制用)
     public List<UserProtocolVersion> findAllByProtocol(Long protocolId){
         return this.lambdaQuery()
diff --git a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/service/protocol/UserProtocolVersionService.java b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/service/protocol/UserProtocolVersionService.java
index 26de8044f..c726716f0 100644
--- a/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/service/protocol/UserProtocolVersionService.java
+++ b/daxpay-platform/daxpay-platform-service/service-system/src/main/java/cn/daxpay/open/platform/system/service/protocol/UserProtocolVersionService.java
@@ -114,6 +114,13 @@ public class UserProtocolVersionService {
                 .orElse(null);
     }
 
+    /// 查询新建草稿可继承的源版本(已发布优先, 否则最新归档; 无则 null)
+    public UserProtocolVersionResult findInheritSource(Long protocolId, String language){
+        return userProtocolVersionManager.findLatestForInherit(protocolId, language)
+                .map(UserProtocolVersion::toResult)
+                .orElse(null);
+    }
+
     /// 复制版本到目标协议(用于复制到其他端, 直接以已发布状态写入)
     @Transactional(rollbackFor = Exception.class)
     public void copyVersion(UserProtocolVersion source, Long targetProtocolId){