Simulation calculation was made to the volume of water gushing in typical section of down line in Xinqidaoliang Tunnel by adopting methods of water dynamics, water equilibrium, water runoff and water analysis. It is found the methods of analysis and water runoff were suitable for calculation of volume of water gushing in this section, but the predicted volume of water gushing was overlarge by adopting methods of water equilibrium and water dynamics. Numerical simulation is a good way to simulate and predict the volume of underground water, which can predict the seepage characteristics of underground water.