diff --git a/calibrate_extrinsic_and_display_in_ros_cn.md b/calibrate_extrinsic_and_display_in_ros_cn.md
index 979f245..2ac8cf5 100644
--- a/calibrate_extrinsic_and_display_in_ros_cn.md
+++ b/calibrate_extrinsic_and_display_in_ros_cn.md
@@ -45,3 +45,4 @@
 ![Calibrate_extrinsic](image_ros/calibrate_extrinsic_04.png)
 
 ![Calibrate_extrinsic](image_ros/calibrate_extrinsic_05.png)
+