diff --git a/weixin/oa_sdk.go b/weixin/oa_sdk.go
index 5551c45..0adb6fe 100644
--- a/weixin/oa_sdk.go
+++ b/weixin/oa_sdk.go
@@ -115,7 +115,28 @@ func (o *OaSdk) UploadFileByByte(file []byte, ext string) (string, string, error
 	if err != nil {
 		return "", "", err
 	}
-	res, err := http.Post(UploadOaMedia, writer.FormDataContentType(), body)
+	token, err := o.getAccessToken()
+	if err != nil {
+		return "", "", err
+	}
+	postType := ""
+	if ext == ".jpg" || ext == ".png" || ext == ".gif" || ext == ".jpeg" {
+		postType = "image"
+	} else if ext == ".mp4" {
+		postType = "video"
+	} else if ext == ".mp3" {
+		postType = "voice"
+	}
+
+	if postType == "" {
+		return "", "", fmt.Errorf("不支持的文件类型")
+	}
+
+	res, err := http.Post(
+		fmt.Sprintf("%s?access_token=%s&type=%s", UploadOaMedia, token, postType),
+		writer.FormDataContentType(),
+		body,
+	)
 	if err != nil {
 		return "", "", err
 	}