Abstract: In order to solve the problems of serious air leakage and high gas concentration in the upper corner of 10201 working face of Bailongshan coal mine, Fluent software based numerical simulation studies are carried out to obtain the change law of working face air volume and gas concentration, the change law of gas distribution and spontaneous combustion oxidation zone in the air inlet side with different lengths of wind-blocking curtains. The results showed that in the range of 0-80 m from the working face to the inlet lane, the air volume of the working face gradually increase. In the range of 0-190 m from the working face to the inlet lane, the gas concentration of the working face gradually decreases with the increase of the length of the wind-blocking curtain. The wind-blocking curtain can reduce the gas concentration in the shallow and central part of the return side of the mining area. But for the deep part of the inlet side and return side of the mining area, the wind-blocking curtain will increase the gas concentration. The installation of the wind-blocking curtain on the inlet side is able to increase the width of the spontaneous oxidation zone on the inlet side of the mining area, reduce the width of the spontaneous oxidation zone on the return side of the mining area. As the length of the windshield increases, the spontaneous combustion oxidation zone on the inlet side of the mining area gradually approaches the working face. The numerical simulation results show that the reasonable length of wind-blocking curtain is 5 m. The application results show that after the curtain installation, the effective air volume of the working face increases, the average gas volume fraction is 0.521% with a decrease of 13.5%, the average carbon monoxide volume fraction is 2.26% with the decrease of 8.1%, and the risk of gas overrun in the upper corner and spontaneous fire in the mining area is reduced.