This paper designs an intelligent stereo garage system based on PLC, which consists of parking space, turntable transposition device, car positioning device and elevator. The control uses Siemens S7-300 PLC as the main station, two S7-200 PLC as the slave station, Ethernet as the form of networking, and MCGS as the human-computer interaction interface. By controlling servo motor, stepping motor, frequency converter and ordinary three-phase asynchronous motor, the switch of elevator door, elevator lift, automobile fixed telescopic bracket motor, clamping motor of bracket, turntable rotation are controlled.