diff --git a/backend/internal/router/app/info.go b/backend/internal/router/app/info.go
index 10f5d01..1002f17 100644
--- a/backend/internal/router/app/info.go
+++ b/backend/internal/router/app/info.go
@@ -216,18 +216,57 @@ func handleAppCheckUpdate(c *gin.Context) {
 		}
 	}
 
-	// 确定下载地址：优先使用完整包地址，其次自定义地址
-	downloadURL := latestVersion.FilePath
-	downloadSize := latestVersion.FileSize
-	downloadHash := latestVersion.FileHash
+	// 确定下载地址
+	var downloadURL string
+	var downloadSize int64
+	var downloadHash string
+	var fullPackageURL string
+	var fullPackageSize int64
+	var fullPackageHash string
+	var isPatchUpdate bool
 
-	// 使用完整包地址（如果有）
-	if latestVersion.FullPackagePath != "" {
-		downloadURL = latestVersion.FullPackagePath
-		downloadSize = latestVersion.FullPackageSize
-		downloadHash = latestVersion.FullPackageHash
+	if latestVersion.UpdateType == "patch" && latestVersion.BaseVersionID != nil {
+		// 最新版本是补丁类型
+		// 检查客户端版本是否是基础版本
+		if clientVersionRecord.ID == *latestVersion.BaseVersionID {
+			// 客户端是基础版本，可以下载补丁包
+			downloadURL = latestVersion.FilePath
+			downloadSize = latestVersion.FileSize
+			downloadHash = latestVersion.FileHash
+			isPatchUpdate = true
+		} else {
+			// 客户端不是基础版本，需要下载完整包
+			if latestVersion.FullPackagePath != "" {
+				downloadURL = latestVersion.FullPackagePath
+				downloadSize = latestVersion.FullPackageSize
+				downloadHash = latestVersion.FullPackageHash
+			} else {
+				// 没有完整包，使用补丁包（可能合并失败）
+				downloadURL = latestVersion.FilePath
+				downloadSize = latestVersion.FileSize
+				downloadHash = latestVersion.FileHash
+			}
+		}
+		// 保存完整包地址作为备选
+		if latestVersion.FullPackagePath != "" {
+			fullPackageURL = latestVersion.FullPackagePath
+			fullPackageSize = latestVersion.FullPackageSize
+			fullPackageHash = latestVersion.FullPackageHash
+		}
+	} else {
+		// 全量版本，直接使用文件路径
+		downloadURL = latestVersion.FilePath
+		downloadSize = latestVersion.FileSize
+		downloadHash = latestVersion.FileHash
+		// 全量版本的完整包就是自己
+		if latestVersion.FullPackagePath != "" {
+			fullPackageURL = latestVersion.FullPackagePath
+			fullPackageSize = latestVersion.FullPackageSize
+			fullPackageHash = latestVersion.FullPackageHash
+		}
 	}
-	// 自定义地址优先级最高
+
+	// 自定义地址优先级最高（覆盖下载地址）
 	if latestVersion.CustomDownloadURL != "" {
 		downloadURL = latestVersion.CustomDownloadURL
 	}
@@ -249,22 +288,19 @@ func handleAppCheckUpdate(c *gin.Context) {
 		"files":           files,
 	}
 
-	// 检查是否有适合客户端版本的增量更新
-	// 查找以客户端版本为基础版本的 patch 更新
-	var patchVersion model.Version
-	err := database.DB.Where("application_id = ? AND update_type = ? AND base_version_id = ? AND publish_status = ?",
-		app.ID, "patch", clientVersionRecord.ID, "published").
-		Order("id DESC").
-		Preload("Files").
-		First(&patchVersion).Error
-
-	if err == nil {
-		// 找到了增量更新
+	// 如果是补丁更新，添加补丁信息
+	if isPatchUpdate {
 		result["is_patch"] = true
-		result["base_version"] = clientVersion
-		result["patch_url"] = patchVersion.FilePath
-		result["patch_size"] = patchVersion.FileSize
-		result["patch_hash"] = patchVersion.FileHash
+		result["patch_url"] = downloadURL
+		result["patch_size"] = downloadSize
+		result["patch_hash"] = downloadHash
+	}
+
+	// 如果有完整包，添加完整包信息作为备选
+	if fullPackageURL != "" {
+		result["full_package_url"] = fullPackageURL
+		result["full_package_size"] = fullPackageSize
+		result["full_package_hash"] = fullPackageHash
 	}
 
 	response.Success(c, result)