Under rainfall-irrigation-evaporation, 2-D soil moisture movement mathematical model including root water uptake function was established, and solved by finite element method based on soil hydrodynamics theory and root zone soil moisture movement characteristic. The model was verified by the data of the measured soil moisture content in filed. The computational results were in accordance with the measured, which indicated that the mathematic model of soil water movement is correct, and that solving of the model with finite element method is feasible. The model can be used to simulate the soil moisture distribution rule.