Abstract: In this paper, AT89 C52 is used to design four modules: key input and display, photosensitive resistance induction, human infrared induction and sound photoelectric alarm. When the light is sufficient, the system does not work. When the light is weak, the system automatically lights up when a pedestrian passes. When the pedestrian is detected to be out of the trigger range, street lights will be the last human activity as the limit of automatic delay of 10 seconds into the third level of brightness, to provide lighting for passing vehicles. The system has the functions of auto-adjusting light, auto-turning on and off and auto-alarming sound and light.