Abstract: In view of problems of low carrying capacity, low safe and reliable performance and low automation control degree existed in original electronic control system of hoist of Wutongzhuang Coal Mine, a reforming scheme of automatic control system of hoist was put forward, and key technical principles were introduced including frequency-conversion speed-regulation system of motor, communication system based on field bus and safety monitoring system. The application results show that average temperature of motor stator is about 10 ℃ lower than that of the original system, average temperature of rotor decreases by about 20 ℃, and temperature measuring element and water cooling unit in stator windings all contribute to reduction of failure rate of the motor; operating speed of the hoist is up to 10 m/s, single hook running time is about 135 s, and lifting load is 25 t which meets design requirements; Profibus and multi-level system architecture were adopted, functional modules, communication interfaces, system services and system monitoring belong to different levels to ensure reliability and scalability of the system.