Abstract: Soil moisture movement under varying-head infiltration is a basic theoretical problem of water storage pit irrigation. According to the fundamental theory of soil moisture dynamics, the complicated varying-head infiltration boundary of water storage pit irrigation was analyzed, the mathematic expression between water level and varying-head infiltration of pit wall was obtained, and the numerical model of soil water movement was established under the condition of water storage pit irrigation. ADI method and Gauess-Seidel iterative method were used to realize the numerical simulation of soil moisture movement under varying-head infiltration of single water storage pit. A series of experiments were conducted to verify the model. The results indicate that the calculated results are in accordance with the experimental results.