Abstract: In view of problems existed in underground high-voltage power system of No.4 Coal Mine of Zhongping Energy Chemical Group Co., Ltd., the paper introduced a reform scheme of real-time monitoring and control system of underground power supply based on industrial Ethernet + field bus. It introduced general design and network structure of the system and gave characteristics and application effect of the system. The actual application showed that the system can ensure real-time, reliability and safety of data transmission.