Abstract: As an important power source for the DC power supply system of power plants, substations and converter stations, the reliability of the battery pack ultimately determines the reliability of the DC system. It summarizes the various problems existing in the battery monitoring system of the substation, and analyzes the current status of the battery nuclear capacity. It developes battery remote feedback discharge and big data monitoring and control system, which can control real-time status, find faulty batteries in time, eliminate hidden safety hazards, effectively improve the service life of the battery, and ensure the uninterrupted power supply system operation.