Abstract: In view of problem that traditional process water system of coal mine cannot real-timely know situations of running of pump and water level of sump with manual operation mode, a monitoring system of process water of coal mine was designed. The system includes many PLC control stations which are used to monitor pump house of surface wastewater treatment plant, underground pump houses and sumps. Each PLC control station collects data of sensors and uploads the data to upper computer through industrial Ethernet, the upper computer dispatches working pump and spare pump according to the data and makes remote operation for electric valve, so as to realize automatic control function. The actual application shows that the system realizes unmanned on duty and remote control for pump houses and improves automation level of coal mine.