According to the impermeability of the floor strata in mining under pressure, the permeability test of the specimen was carried. Considering the relation between permeability-strain curve and rock failure process, the relationship among permeability, strain and stress of rock was analyzed based on the permeability-strain curves and permeability-stress curves under complete stress-strain path. The result shows that the permeability of the specimen can be divided into the original void permeability and loading failure permeability. The original void permeability mainly appeared at the compaction-elastic stage and the loading failure permeability is mainly at the stable and unstable development stage. The stress and strain at the sudden increase point is the 60% to 80% of the peak point. For the most rocks, the permeability peak is at the post-peak stage, some at the peak point, and a few at the pre-peak stage, which is the soft rocks mostly. The deformation and failure of the argillaceous rocks is more serious than the limestone and sandstone rocks. The ratio of the stress and strain at the sudden increase point and the peak point or the ratio of the strain at the maximum permeability and the sudden increase point of the permeability can better reflect the law of the changes of permeability.