Abstract: Coal mining machine mostly adopts additional DC power protection, which is characterized by comprehensive protection, capacitive current compensation, and simple action value adjustment, but the phenomenon of leakage protection device misoperation and tripping occurs in actual production.False action frequently occurs for Shihang coal mine mining machine traction motor leakage protection circuit in the working process due to the influence of the inverter device.For this reason, the coal mining machine leakage protection system is studied, the deficiencies of current protection circuit are analyzed, and after analyzing the interfering signals, the solution of using subtraction circuit to offset the interfering signals is proposed and simulated.The practical results show that the above solution is simple and easy to realize, which can improve the reliability of the traction motor leakage protection device, avoid unnecessary production stoppage, and can improve the production efficiency.