diff --git a/car/ChassisM2.md b/car/ChassisM2.md
index 1bba479..dd98cd0 100644
--- a/car/ChassisM2.md
+++ b/car/ChassisM2.md
@@ -219,7 +219,7 @@ odom -> base_link
 
 ### 3.1 底盘连接
 
-将PM1的串口线插入笔记本电脑或工控机，打开底盘电源和急停开关
+将M2的串口线插入笔记本电脑或工控机，打开底盘电源和急停开关
 
 打开Terminal输入