diff --git a/backend/internal/controllers/file.go b/backend/internal/controllers/file.go
index 9facf2f..4409637 100644
--- a/backend/internal/controllers/file.go
+++ b/backend/internal/controllers/file.go
@@ -90,7 +90,9 @@ func CreateUploadTask(c *echo.Context) error {
 		CreatedAt: time.Now().Unix(),
 		Expire:    uploadTaskExpire,
 	}
-	err = models.SetRedisFileInfo(fileId, newFileInfo)
+	err = models.SetRedisFileInfo(fileId, func(fileInfo *models.RedisFileInfo) *models.RedisFileInfo {
+		return &newFileInfo
+	})
 	if err != nil {
 		return utils.HTTPErrorHandler(c, err)
 	}
@@ -233,8 +235,9 @@ func FinishUploadTask(c *echo.Context) error {
 	}
 
 	// 更新文件信息
-	err = models.SetRedisFileInfo(r.FileId, models.RedisFileInfo{
-		FileType: models.FileTypeUpload,
+	err = models.SetRedisFileInfo(r.FileId, func(fileInfo *models.RedisFileInfo) *models.RedisFileInfo {
+		fileInfo.FileType = models.FileTypeUpload
+		return fileInfo
 	})
 	if err != nil {
 		return utils.HTTPErrorHandler(c, err)
diff --git a/backend/internal/services/file.go b/backend/internal/services/file.go
index 8ff5ad5..68ccafc 100644
--- a/backend/internal/services/file.go
+++ b/backend/internal/services/file.go
@@ -71,18 +71,13 @@ func MergeFileSlices(fileId string, uploadPath string) (string, error) {
 		if err != nil {
 			return "", fmt.Errorf("打开切片文件失败: %v", err)
 		}
-		defer sf.Close() //nolint:errcheck
-		for {
-			n, err := sf.Read(buffer)
-			if err == io.EOF {
-				break
-			}
-			if err != nil {
-				return "", fmt.Errorf("读取切片文件失败: %v", err)
-			}
-			if _, err := destFile.Write(buffer[:n]); err != nil {
-				return "", fmt.Errorf("写入合并文件失败: %v", err)
-			}
+
+		if _, err := io.CopyBuffer(destFile, sf, buffer); err != nil {
+			sf.Close() //nolint:errcheck
+			return "", fmt.Errorf("合并切片文件失败: %v", err)
+		}
+		if err := sf.Close(); err != nil {
+			return "", fmt.Errorf("关闭切片文件失败: %v", err)
 		}
 	}
 	return mergeFilePath, nil