Abstract: In view of the problem of remote monitoring failure caused by the failure of monitoring substation of coal mine power supply monitoring system, a redundant monitoring sub-station coal mine power supply monitoring system is designed. The two monitoring sub-stations of underground substation are hot standby for each other, the monitoring sub-stations maintain the heartbeat through optical fiber communication, the RS485 bus communication hardware interlock circuit between the two monitoring sub-stations and the integrated power protector in the high and low voltage power distribution device is designed, and the hot standby software of monitoring substation is designed. The field application shows that when one monitoring substation is abnormal, the other monitoring substation can be put into operation within 30 s, which is beneficial to improving the reliability of coal mine power supply monitoring system.