Abstract: In order to improve the safety of coal mine equipment, an automatic fire prevention and extinguishing technology is studied by flame and smoke sensors, which can detect flame and smoke of surveillance areas continuously and send information to PLC controller. The solenoid valves are opened to spray extinguishing medium and extinguish flame. By industrial test of refueling chamber, rationality and reliability of the system is verified and effective range is no less then 6 m², which can ensure the safety of chamber and electrical equipment.