diff --git a/src/core/apis/file.ts b/src/core/apis/file.ts
index 52a36557..3d457720 100644
--- a/src/core/apis/file.ts
+++ b/src/core/apis/file.ts
@@ -201,7 +201,7 @@ export class NTQQFileApi {
             elementType: ElementType.VIDEO,
             elementId: '',
             videoElement: {
-                fileName: fileName || _fileName,
+                fileName: (fileName || _fileName).replace(/\.[^/.]+$/, '.mp4'),
                 filePath: path,
                 videoMd5: md5,
                 thumbMd5,