diff --git a/README.md b/README.md
index 9d9cd89..6059be3 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Please follow the guide doc to install the SDK on different platforms.
 
 * [API Doc](https://github.com/slightech/MYNT-EYE-S-SDK/releases): API reference, some guides and data spec.
   * en: [![](https://img.shields.io/badge/Download-PDF-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893965/mynt-eye-s-sdk-apidoc-2.3.1-en.pdf) [![](https://img.shields.io/badge/Download-HTML-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893979/mynt-eye-s-sdk-apidoc-2.3.1-en.zip) [![](https://img.shields.io/badge/Online-HTML-blue.svg?style=flat)](https://slightech.github.io/MYNT-EYE-S-SDK/)
-  * zh-Hans: [![](https://img.shields.io/badge/Download-PDF-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893985/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans.pdf) [![](https://img.shields.io/badge/Download-HTML-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893986/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans.zip) [![](https://img.shields.io/badge/Online-HTML-blue.svg?style=flat)](http://doc.myntai.com/resource/api/mynt-eye-s-sdk-apidoc-2.3.1-en/mynt-eye-s-sdk-apidoc-2.3.1-en/index.html)
+  * zh-Hans: [![](https://img.shields.io/badge/Download-PDF-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893985/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans.pdf) [![](https://img.shields.io/badge/Download-HTML-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK/files/2893986/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans.zip) [![](https://img.shields.io/badge/Online-HTML-blue.svg?style=flat)](http://doc.myntai.com/resource/api/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans/mynt-eye-s-sdk-apidoc-2.3.1-zh-Hans/index.html)
 * [Guide Doc](https://github.com/slightech/MYNT-EYE-S-SDK-Guide/releases): How to install and start using the SDK.
   * en: [![](https://img.shields.io/badge/Download-PDF-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK-Guide/files/2893975/mynt-eye-s-sdk-guide-2.3.1-en.pdf) [![](https://img.shields.io/badge/Download-HTML-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK-Guide/files/2893996/mynt-eye-s-sdk-guide-2.3.1-en.zip) [![](https://img.shields.io/badge/Online-HTML-blue.svg?style=flat)](https://slightech.github.io/MYNT-EYE-S-SDK-Guide/)
   * zh-Hans: [![](https://img.shields.io/badge/Download-PDF-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK-Guide/files/2893997/mynt-eye-s-sdk-guide-2.3.1-zh-Hans.pdf) [![](https://img.shields.io/badge/Download-HTML-blue.svg?style=flat)](https://github.com/slightech/MYNT-EYE-S-SDK-Guide/files/2893997/mynt-eye-s-sdk-guide-2.3.1-zh-Hans.pdf) [![](https://img.shields.io/badge/Online-HTML-blue.svg?style=flat)](http://doc.myntai.com/resource/sdk/mynt-eye-s-sdk-guide-2.3.1-zh-Hans/mynt-eye-s-sdk-guide-2.3.1-zh-Hans/index.html)