Abstract: In order to accurately judge the effective extraction region of mining-induced pressure relief and extraction in high gas and low air permeability coal seam, and improve gas extraction effect, seepage test and theoretical analysis are adopted to study the impact of stress on coal permeability during mining process. The results show that, the process of coal permeability changing can be divided into three stages with the stress changing caused by mining. In elastic deformation stage, coal permeability will decrease with the increase of stress; when coal body reaches the yield point to coal damage stage, plastic deformation appears and mining-induced fractures form in coal with the increase of stress, coal permeability begins to increase slowly; coal is in pressure relief state after it is destroyed, coal permeability will increase drastically with the decrease of stress. Finally, the accuracy of study results is verified by the coal seam gas extraction effect.