Abstract: In view of requirement of relay and amplification of CAN bus signal due to lots of nodes and long transmission distance of coal mine field equipments and problems of normal software CAN-bus repeater such as data frame time-delay, frame loss, large power consumption, non self-adaptive rate and so on. In order to solve above problems, a mine-used hardware CAN-bus repeater was designed. The repeater is mainly composed of D trigger, XOR gate and CAN transceiver. The D trigger is used to control level signal transmission, the XOR gate is used to generate pulse signals for D trigger flip-flop, and the CAN transceiver accesses data into CAN-bus network, so as to realize transparent transmission of CAN-bus signal. The simulation and experiment test results show that the mine-used hardware CAN-bus repeater can correctly transmit CAN data frame, effectively improve bus level and signal quality, and increase communication distance. Compared with software CAN-bus repeater, the mine-used hardware CAN-bus repeater has advantages such as low power consumption, little time-delay, no frame loss, rate self-adaption and so on, which is applicable for CAN-bus network with high requirements about data frame time-delay and power consumption in coal industry field.