Abstract: In order to get the permeability rapidly and exactly under different stress state, a method that combined lattice Boltzmann with uniaxial compression test is proposed to study the rock and coal permeability. Firstly, a destructive compression test was made on the coal-rock, and the stress-strain curve is obtained. And the coal-rock crack images under different stress levels are recorded during the process of compression. Then a simulation program of pore scale lattice Boltzmann is written and verified by Grenoble test. This program can read the crack images and simulate the flow of fluid in the crack, obtain the fluidity pressure and flow velocity. The value of permeability of different crack images can be calculated on the basis of Darcy equation. As a result, the relation curve of the stress-strain and coal-rock permeability is obtained. Through data fitting, we get the strain - permeability relationship, which is compared with the strain - permeability relationship in the literature.