An iterative model was proposed to approximate the Richards' equation by coupling the soil water budget method and the analytical solution of steadystate transpiration flux, and was used to analyze the variation of soil water storage with groundwater table and its influences on soil water evaporation and groundwater evaporation. The coupled model was verified against the Hydrus-1D model. Then, the model was applied to simulation of the variation of soil water storage and transpiration flux at the groundwater depths of 0.4 m, 0.6 m, and 1.5 m at the Wudaogou Hydrological Experimental Station in Anhui Province, and the results were compared with observations from three lysimeters. The results indicate that the coupled model can effectively simulate the effects of the groundwater table on soil water storage and evaporation flux under capillary forces, and conduct a reasonable inversion of the hydraulic conductivity and pore size distribution index at different groundwater depths.