Abstract: There exists shortcomings such as excessive short-circuit capacity, single power distribution structure, relatively low power factor, insufficient intelligence level and others in the downhole power supply system of Wanglou Coal Mine, which restrict the reliability and energy-saving benefits of power supply. For this reason, a multi-level comprehensive governance scheme is constructed: through the replacement of high impedance transformers, the separate operation of busbars, and the application of fast current limiting devices to manage and control short-circuit currents; Upgrade the PBG switch to an intelligent device that integrates arc light and fiber optic longitudinal differential protection, and introduce SVG to achieve dynamic reactive power compensation; Adopt the IEC 61850 communication statute to build a redundant industrial Ethernet ring network, and achieve "six remote" and remote tuning function. After implementation, the short-circuit current of the system is controlled within 18 kA, the fault isolation time is shortened to 25 ms, the power factor is improved to 0.95, the voltage loss is reduced to below 3%, and the recovery time of standby power supply auto-switching is compressed to 150 ms. The safety, stability, and energy-saving level of the power supply system are significantly improved.