In order to improve the gas drainage effect and solve the problem of gas overrun in the working face of Gaohe Mine, a field test was carried out on the E2307 fully mechanized caving face. The influence of the leading support stress on the gas drainage effect was studied. The results showed that the relationship between the distance from the working face and the amount of pure extraction was generally regular. It could be divided into 4 stages, original extraction, weakening of extraction, growth of extraction and attenuation of extraction. Among them, the extraction volatility of the two stages of extraction growth and extraction attenuation was significantly improved compared with the original extraction stages, reaching 4~6 times of the original stage. Through the research on the law of pressure relief and extraction, the improvement and optimization measures of gas drainage pipe network were proposed, which reduced the air leakage rate and prolonged the drainage time, with good application results.