Abstract: The paper introduced a design scheme of monitoring and control system of mine main ventilator, discussed structure, functions and designs of hardware and software of the system in details. The hardware of the system takes S7-300 PLC as core, and the software uses configuration software INTouch9.5 to achieve. The system adopts three control modes of manual control, local control and remote control, and realizes real-time monitoring of operation of main ventilator.