For high gas mines, it is necessary to solve the problem of large gas emission during the mining of the working face. 12507 working face of Tunlan Mine was taken as an example, the gas source of the 12507 working face was analyzed. On this basis, the optimization measures of ventilation system based on reasonable configuration of ventilation volume, reduction of air leakage in goaf and reduction of ventilation pressure difference were proposed, with comprehensive gas drainage measures such as pre-drainage along the seam, pre-drainage in the upper adjacent layer high and low long boreholes, pre-drainage in the bottom adjacent roadway in the bottom coal seam, and pipe mining in the goaf. The above measures ultimately brought the gas drainage rate to 86%, and the gas concentration of the air return flow and the upper corner of the air can be controlled within a safe range, which effectively guaranteed the safe and efficient mining.