In order to improve the automation of the sewage pump and prevent the motor from being accidentally burned due to the overflow of the sludge collection pit, the labor intensity of the operator was reduced, the working environment and and the production efficiency of the coal washing plant were improved. Through the automatic control system transformation of the sludge collection pit sewage pump in the concentrating workshop of Yungang Coal Washing Plant, two liquid level sensors and grounding wires in the sludge collection pit equipment were used to control the sewage pump to start and stop, sewage discharge was realized, without abnormal pump alarm. Through one year of on-site application, the automatic control system of the sewage pump was running well without failure, which ensured the safe operation of the equipment, improved production efficiency, and achieved good economic benefits, with a profit of 6.21 million yuan.