Abstract: In order to improve reliability and real-time of detection data and control data of underground substation,the paper proposed a design scheme of remote monitoring and control system of underground substation based on CAN bus and Ethernet.The system uses high-voltage switch integrated protector to convert various protection and detection signals of underground substation to CAN bus data,and each substation sets one or more monitoring substations.The monitoring substation uses CAN bus-Ethernet protocol converter developed by PIC18F4680 and ENC28J60 to convert CAN bus data to Ethernet data frames,then transmit data by Ethernet.The upper computer of surface monitoring and control center uses multithread technology to convert Ethernet data frames to Modbus protocol data,which can realize functions of remote monitoring and control for underground substation.The actual application showed that network structure of using CAN bus and Ethernet can meet requirements of remote monitoring and control system of underground substation perferably.