diff --git a/storage/minio.go b/storage/minio.go
index 21adf50..4eb3a83 100644
--- a/storage/minio.go
+++ b/storage/minio.go
@@ -63,9 +63,13 @@ func (s *Minio) Put(fileName, objectName string, onProcess func(fsize, uploaded
 
 	objectName = strings.TrimLeft(objectName, "/ ")
 	ext := strings.TrimLeft(path.Ext(fileName), ".")
+	contentType := ext2ContentType(ext)
+	if contentType == "" {
+		contentType = detectContentType(fileName)
+	}
 
 	_, err := s.client.FPutObjectWithContext(ctx, s.config.Bucket, objectName, fileName,
-		minio.PutObjectOptions{ContentType: ext2ContentType(ext)})
+		minio.PutObjectOptions{ContentType: contentType})
 	if err != nil {
 		log.Errorf("upload file to minio error:%s", err.Error())
 		return err
diff --git a/storage/util.go b/storage/util.go
index c749723..a99f44f 100644
--- a/storage/util.go
+++ b/storage/util.go
@@ -115,6 +115,24 @@ func ext2ContentType(ext string) string {
 	}
 }
 
+// detectContentType 从文件内容检测 MIME 类型
+func detectContentType(filePath string) string {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return ""
+	}
+	defer f.Close()
+
+	// 读取前 512 字节用于检测
+	buf := make([]byte, 512)
+	n, err := f.Read(buf)
+	if err != nil && err != io.EOF {
+		return ""
+	}
+
+	return http.DetectContentType(buf[:n])
+}
+
 func Download(url, path string) error {
 	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
 	stat, err := f.Stat()