diff --git a/zh-cn/application-dev/media/image-tool.md b/zh-cn/application-dev/media/image-tool.md
index 7fc7947bb0dd804e32e25b4302aea0578c4adb60..e628d615f3cd9075b8231cc6e66840347451ebf9 100644
--- a/zh-cn/application-dev/media/image-tool.md
+++ b/zh-cn/application-dev/media/image-tool.md
@@ -37,7 +37,7 @@ EXIF信息的读取与编辑相关API的详细介绍请参见[API参考](../refe
    
    // 编辑EXIF信息
    imageSource.modifyImageProperty('ImageWidth', '120').then(() => {
-     const width : number = imageSource.getImageProperty("ImageWidth");
+     const width : Promise<string> = imageSource.getImageProperty("ImageWidth");
      console.info('The new imageWidth is ' + width);
    })
    ```