Abstract: To study the influence of gas pressure on the bioreactor landfill settlement, the bioreactor landfill is simplified as a one-dimensional gas seepage field. Incorporating Darcy's law, ideal gas law, the principle of effective stress and the theory of fluid dynamics in porous media, it is assumed that the bioreactor landfill leachate can fully infuse circularly into the wastes. Then, based on the conservation of gas mass, a mathematical model is developed for the settlement under the action of gas pressure in a bioreactor landfill according to the relationship between the air pressure difference between atmosphere and piled wastes in landfill and landfill settlement during gas dissipation. A finite difference method is used to solve the model. With an exemplification, the model is verified available to predict well the bioreactor landfill settlement.