Based on the current status of substations in Sanjiaohe Mine underground mining area, an intelligent unattended transformation plan was proposed and implemented. The transformed substation can effectively avoid the problem of power supply overstepping trips and realize unattended operation. The ground centralized control center can be used to remotely monitor and control the underground substation. If faults were found during the monitoring process, an alarm can be issued in time and a response plan can be given. Practice showed that the substation with intelligent control system ensured the stability of the underground power supply system and created benefits for coal mine enterprises.