Abstract: Abstract：According to the response characteristics of tectonic coal to gas pressure, experimental studies about permeability of Two kinds of different coal samples were carried out with indigenously developed and improved experiment facility for triaxial seepage flow test to fluid-solid-thermal coupling gas filled coal. The results shows that permeability variation with gas pressure of coal samples have apparent Klinkenberg effect, the permeability changes of soft coal and hard coal samples conform to quadratic polynomial function. Under different confining pressures, the permeability of two kinds of coal sample with gas pressure changes greatly, Klinkenberg effect and inflection is also inconsistent, which is mainly affected by the sample adsorption constant. The reason for decreased first then increased of coal permeability: resulting in a reduced permeability of Klinkenberg effect and gas adsorption effect of coal matrix expansion under confining pressure and axial compression in the beginning stages, later pore pressure increase leads to increase the permeability of the coal plays a dominant role, those co-produced the effect. The research results provide a theoretical basis to improve coal-bed methane extraction rate.