In order to solve problems of high cost, frequent faults, difficult maintenance and unreliable cable transmission of existing monitoring modes of spontaneous combustion in goaf, a monitoring system of spontaneous combustion in goaf was designed by use of technologies of wireless RF and CAN bus, and whole structure, main hardware parts and realization of key technologies of the system were introduced in details including frequency of wireless communication, working time sequence of probe, working flow of wireless receiving substation and control protocol of wireless route. The testing result showed the system can set up a network quickly and real-timely collect and correctly transmit temperature data of monitored points when distance between two probes is more than 150 m, and working life of the probe acheives 90 d.