Abstract: The paper put forward a design scheme of explosion-proof and intrinsic safety DC stabilized UPS used in coal mine based on the principle and characteristics of intrinsic safety power supply, introduced design of main circuit of the power supply. The power supply uses LM317 chips to realize voltage stabilization, which has advantages of convenient to use, simple protection circuits, high conversion efficiency and low cost. The test results showed that the power supply reaches intrinsic safety standard and meets with demands of safe electrical equipments.