Control system affects the performance and useful life of internal combustion vehicle. Implementations of internal combustion engine car’s control system design based on GCY520 is presented. According to system function, the system is divided into hardware design and software design.The hardware design contains cpu module,communication module,input/output module,temperature module,counting module and two LCD monitors.The software design realizes logical control based on C language and ladder diagram.Finally we put the system into the internal combustion vehicle cab to test the performance. The results show that the control system runs stably and can meet the needs of users well.