The working face of 3210 Xinyuan mine adopted press-in Y-ventilation, and the gas detector detected that the gas concentration accumulated during the recovery process, which caused hidden danger to the mine safety. In order to ensure the safety of the recovery, fluent software was used to model the entire recovery face, and after numerical simulation, it was concluded that the gas accumulated in the fissure zone above the mine void. According to the numerical simulation, the gas concentration in the working face, mining area and along the goaf was controlled below 0.6%, and the gas concentration was more effectively controlled, which provided a safety guarantee for coal production.