Abstract: In order to eliminate the safety hidden danger of the gas surge when mining in 11501 full mechanized working face of long wall with gentle inclined thick coal seam,reduce the error of traditional gas linear model analysis,on the basis of fully considering the influence of the dynamic process of gas adsorption/desorption,the model of gas seepage characteristic was modified accordingly,and based on the modified model,the numerical simulation of gas migration during mining in the working face was carried out,the effect of high level borehole gas extraction was investigated on site.The results show that with the optimal high level borehole gas extraction,the amount of gas in fully mechanized working face increases by 50.1% and the amount of gas in coal seam decreases by 40.6%.