Abstract: In view of problem that common accumulators used in underground coal mine have obvious constraints, the paper analyzed electricity demands of coal mine emergency facilities and characteristics of dry-charged lead-acid battery, developed large capacity start-up type power supply for coal mine emergency facilities based on dry-charged lead-acid battery technology. The theory analysis and experiment result of product show that the power supply does't produce hydrogen and can be used in coal mine, has good consistency of group working performance and large capacity, and its electrical performance can satisfy demands of coal mine emergency facilities.