Based on the calculation of the power and voltage levels of the main equipment of 3 300 V, 1 140 V and 660 V in the 1751 working face of Gequan Mine, the power supply scheme of the working face and the capacity of the mobile substation are determined. The overall power supply network is calculated and analyzed, and the overall rationality of the power supply design is determined according to the long-term operating current, start-up and normal operating state voltage loss. After field trial operation, the overall operation of the power supply system is stable, which lays a good foundation for the safe and efficient mining of the 1751 working face of the mine.