This article describes a system device capable of displaying a car outside sounds, the system device sound signals collected by the sound sensor , combined with the single-chip analytical processing Finally, LED lights, buzzer and other electronic actuator smart car external speaker sound source direction and strength of the drivers are able to accurately determine the rear of the vehicle the location and intentions, in order to take more appropriate driving route and speed, so that the operation of the vehicle more intelligent, is conducive to maintaining the smooth flow of traffic, more effective in reducing traffic accidents, to further improve automotive safety system, greatly improves the safety performance of vehicles.