Abstract: In the seepage of low permeability coal seam, the slippage effect is obviously affected by the seepage effect. In the current CBM seepage model, the slippage coefficient is regarded as a constant. Based on this, a gas seepage model with dynamic slip coefficient is established, and the finite element numerical software is used for simulation analysis. The variation law of permeability and slippage coefficient of coal reservoir with extraction time is studied after considering dynamic slippage effect. The difference of pore pressure in coal reservoir is compared when dynamic slip coefficient and fixed initial slip coefficient are considered. The results show that the slip coefficient increases first and then decreases, and the permeability decreases first and then increases with the increase of extraction time. When the dynamic slippage effect is taken into account, the reduction of pore pressure at all places of the coal reservoir after 30 d of extraction is smaller than that without consideration, and the difference between the two is larger with the lower initial permeability.