本论文主要介绍了红、绿、黄三色交通信号灯较简单的数字逻辑控制电路设计及其原理。本设计方案由定时器、分频器、扭环形计数器、十进制减法器及七段显示译码器实现交通灯红、黄、绿三色的自动切换，在切换灯光颜色的同时进行时间定时状态的切换，使整个交通灯系统得以按照事先设定的定时时间顺利运转。-This paper focuses on the red, green, yellow three-color traffic signal control of the relatively simple digital logic circuit design and its principles. The design by the timer, divider, twisted ring counter, decimal subtraction device and the seven-segment display decoder to achieve traffic lights red, yellow and green three-color auto-switching, in the light color at the same time switching time of regular state switch, so that the whole traffic light system to time in accordance with pre-set timer running smoothly.