Based on energy conservation equation and Darcy’s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% (less than 5%), which was acceptable in engineering application. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/(m·K) and 1.46 W/(m·K), respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.