To know the dynamic characteristics of shale gas reservoirs’ production and to improve shale gas well production, it is very important to research on shale gas seepage mechanism and production evaluation. According to the shale gas seepage mechanism, adsorption and desorption characteristics, the diffusion mechanism and mass conservation theory in shale gas development, the dual pore medium shale gas reservoir mathematical model is set up. The mathematical model is built by the finite difference method based on starting pressure gradient, slippage effect and the isothermal adsorption principle, then program to solve it. Analyze the Langmuir volume, Langmuir pressure, starting pressure gradient and slippage coefficient and other factors on the impact of shale gas wells production.