Abstract: In view of the contradiction between the capacity and impact resistance of mine intrinsically safe power supply, an intrinsically safe power supply with adjustable capacity and protection time, self-recovery and slow start function is designed. Through the research on the protection form and working mechanism of intrinsically safe power supply, combined with the analysis of the load impact characteristics and the working mechanism of cut-off intrinsically safe power supply, this paper discusses the relationship between power capacity and protection time, the improvement of anti-impact technology, self-recovery technology and slow start technology, introduces in detail the realization process of over-current protection, short circuit protection, over-voltage protection, self-recovery and slow start circuit, and gives the solution. It resolves the contradiction between capacity and impact resistance, and provides high-quality power supply guarantee for the stable operation of mine electronic equipment.