diff --git a/rt-thread-version/rt-thread-standard/application-note/components/at/an0014-at-client.md b/rt-thread-version/rt-thread-standard/application-note/components/at/an0014-at-client.md
index 028dcc23bdb5901a11d3618a0b62288821b1d72f..71af694ec5a067427793ec99520395ad1edc0e96 100644
--- a/rt-thread-version/rt-thread-standard/application-note/components/at/an0014-at-client.md
+++ b/rt-thread-version/rt-thread-standard/application-note/components/at/an0014-at-client.md
@@ -48,6 +48,9 @@ AT Client 配置选项介绍如下：
 - Enable print RAW format AT command communication data： 配置开启收发数据实时打印功能。
 - The maxinum length of AT Commonds：配置发送 AT 命令的最大数据长度
 
+除此以外还需开启libc，打开方法如下：
+![开启libc](https://images.gitee.com/uploads/images/2021/0327/155905_f7485bbb_5508125.png "开启libc.png")
+
 配置完成，保存并退出配置选项，输入命令 scons --target=mdk5 生成 MDK 工程；
 
 ### AT Client 添加示例