diff --git a/src/Record/MP4.cpp b/src/Record/MP4.cpp
index a0152ef1..0dd1756a 100644
--- a/src/Record/MP4.cpp
+++ b/src/Record/MP4.cpp
@@ -93,6 +93,7 @@ void MP4File::openFile(const char *file,const char *mode) {
 
     //创建智能指针
     _file.reset(fp,[file_buf](FILE *fp) {
+        fflush(fp);
         fclose(fp);
     });
 }
diff --git a/src/Record/MP4Muxer.h b/src/Record/MP4Muxer.h
index eef8def9..f2e3fbd2 100644
--- a/src/Record/MP4Muxer.h
+++ b/src/Record/MP4Muxer.h
@@ -25,6 +25,8 @@ namespace mediakit{
 
 class MP4Muxer : public MediaSinkInterface, public MP4File{
 public:
+    typedef std::shared_ptr<MP4Muxer> Ptr;
+
     MP4Muxer(const char *file);
     ~MP4Muxer() override;
 
@@ -42,9 +44,13 @@ public:
      */
     void resetTracks() override ;
 
+    /**
+     * 手动关闭文件(对象析构时会自动关闭)
+     */
+    void closeMP4();
+
 private:
     void openMP4();
-    void closeMP4();
     void stampSync();
 
 private:
diff --git a/src/Record/MP4Recorder.cpp b/src/Record/MP4Recorder.cpp
index bf0966a9..1f247354 100644
--- a/src/Record/MP4Recorder.cpp
+++ b/src/Record/MP4Recorder.cpp
@@ -75,7 +75,7 @@ void MP4Recorder::asyncClose() {
         //获取文件录制时间，放在关闭mp4之前是为了忽略关闭mp4执行时间
         const_cast<MP4Info&>(info).ui64TimeLen = ::time(NULL) - info.ui64StartedTime;
         //关闭mp4非常耗时，所以要放在后台线程执行
-        const_cast<MP4Muxer::Ptr &>(muxer).reset();
+        muxer->closeMP4();
         //临时文件名改成正式文件名，防止mp4未完成时被访问
         rename(strFileTmp.data(),strFile.data());
         //获取文件大小