Abstract: In order to investigate the permeability evolution law of floor surrounding rock in “three soft” coal seam of high stress zone during the upper protective seam mining, taking the protective seam mining in Ji₁₅-23130 working face of Henan Pingdingshan No.4 mine as the research object, similar experiments are carried out. The results show that the closer distance of the protective layers are, the larger displacement of the bottom is, the higher peak value of the stress curve is, and the smaller the minimum value is, the higher the permeability coefficient is. The permeability coefficient of floor in upper protective layer mining process has successively experienced three stages, they are “slow down - increase dramatically - slow down again”, and there is little difference in the improvement of permeability coefficient at different positions of the same layer. The test also shows that the abrupt change and pressure relief in the process of upper protection layer mining is the important reason for the abnormal gas emission in the mining face.