Abstract: Aiming at the problems that the current mine intrinsically safe power supply has slow protection response speed and low output power, which cannot meet the needs of underground electricity and restrict underground integration and intelligent production, an intrinsically safe short-circuit protection based on the rate of change of fault current is designed. Circuit. In this paper, the intrinsically safe power supply is equivalent to a potential capacitance circuit and the short-circuit fault characteristics are analyzed. It is found that the fault current rises rapidly and abruptly occurs after a short-circuit; an intrinsically safe short-circuit protection circuit based on the rate of change of the fault current is designed, which can quickly and accurately detect the intrinsically safe power supply Short-circuit fault; Intrinsic safety performance test results show that: after a short-circuit fault, the transient output energy is 80.667μJ, self-recovery and soft-start performance are stable, and meet the design requirements.