Abstract: In view of problems of bad real-time performance and short communication distances in master-slave communication mode based on RS485 bus used in monitoring and control and early-warning system of mine, the paper proposed a design scheme of mine-used communication substation based on CAN bus. It introduced design of hardware and software of the substation in details. The substation realizes upload urgent data timely by function definition of ID number and data of CAN message in application-layer protocol of CAN bus. The experiment result showed that the substation meets with communication requirements of coal mine underground with reliable communication and high real-time performance.