Abstract：Lots of researches have proved that adsorbed gas-coal can generate swelling deformation and when the swelling deformation is restricted，swelling stress can be produced. Thus，according to the equilibrium condition of load，the relations of effective stress and swelling stress of coal are studied；and the expressions of effective stress and swelling stress are established. Based on the expressions and the basic idea of fluid-solid coupling seepage theory，the mathematical model of fluid-solid coupled flow of coal-bed gas，which considers the swelling stress of adsorption，is proposed；and the finite difference method and finite element method are employed to calculate the numerical value. By comparing the simulation results of fluid-solid coupled flow without considering the swelling stress of adsorption，it is shown that gas pressure with decreases more much than that without considering the swelling stress of adsorption. So the swelling stress of adsorption can not be ignored.
