Abstract: In order to solve problems of small output power, low working frequency, large output ripple and high fault rate, the paper proposed a design scheme of applying DSPIC30F1010/2020 digital control chip in intrinsic safety switching power supply, gave the whole structure of the switching power supply, and emphatically introduced design of hardware circuit of the switching power supply and software of the switching power supply's digital controller. The results of theoretical analysis, global design, simulation, circuit debugging and safe spark experiment verified the feasibility of applying digital control technology in intrinsic safety switching power supply.