In view of the large gas content in the coal seam of the III1308 fully mechanized working face in Yangcun Coal Industry of Shanxi Province, it is easy to accumulate a large amount of gas in the goaf and to concentrate a large amount of emission, resulting in the gas overrun in the upper corner, it is proposed to adjust the original working faces‘three-in-one-return’ventilation mode to the parallel double U ventilation mode, increase the ventilation capacity of the working face, and dilute the gas in the goaf and the upper corner. On this basis, the original working face drainage system is optimized, and the combined gas drainage mode of the working face is increased, including large-aperture high-level borehole drainage, high-level drilling field drainage, ground mining well drainage and upper corner drainage. The application results show that after the optimization of ventilation mode and drainage system, the gas concentration in the upper corner and return air of the working face is significantly reduced, and there is no gas overrun phenomenon during mining. The average gas discharge of the working face is reduced from 6.58 m3/min to 3.2 m3/min, and the gas control effect is better.