In order to solve the safety problem of mining under pressure in No.18502 face of No.8 coal seam in Malan Mine, through comprehensive geophysical exploration technology, the water abundance characteristics of the Ordovician limestone aquifer and the water conductivity of the structure in the mining area were identified. And it was concluded that the Ordovician limestone aquifer had a certain risk of water outburst by using numerical simulation and water outburst coefficient evaluation. Based on the hydrogeological conditions in the mining area, the comprehensive water prevention and control measures of setting fault waterproof coal pillar and floor grouting reinforcement were put forward, which ensured the safe mining under pressure.