diff --git a/Software/Development/OperatingSystem/Linux/User/Modules/GPIO/用户态_GPIO_操作指南.md b/Software/Development/OperatingSystem/Linux/User/Modules/GPIO/用户态_GPIO_操作指南.md
index e945029..771a590 100644
--- a/Software/Development/OperatingSystem/Linux/User/Modules/GPIO/用户态_GPIO_操作指南.md
+++ b/Software/Development/OperatingSystem/Linux/User/Modules/GPIO/用户态_GPIO_操作指南.md
@@ -52,6 +52,8 @@ echo “rising” > edge
 echo “falling” > edge
 # 边沿触发中断
 echo “both” > edge
+# 翻转电平，输入非零的数即上升沿变为下降沿
+echo 3 > active_low
 cd  ..
 # 删除导出的 GPIO
 echo 167 > unexport