利用有限元方法 ,建立了非饱和土壤水流动的数值计算模型 ,用以模拟均质土壤 ,地下水埋藏很深且在不同的初始和边界条件下的水分运动 .对于入渗或蒸发问题 ,用通常的离散方法容易产生振荡非物理解 .我们采用有限元集中质量法 ,将质量矩阵的非对角元集中到主对角元 ,避免了这种非物理解的产生 ,并且较好地处理了这类边界条件 . Using finite element method, a numerical model of unsaturated soil water flow was established to simulate homogeneous soil with deep groundwater burial and water movement under different initial and boundary conditions. For infiltration or evaporation problems, Of the discrete method is prone to oscillation of non-physical solution.We use the finite element concentration method, the mass matrix of non-diagonal elements to the main diagonal elements, to avoid this non-physical solution, and better handle this Class boundary conditions.