Based on the finite element analysis method, changing different parameters is used to improve the heat storage efficiency of the traditional large-scale heat storage pit. Three different pit models and three different water distributors with different inlet velocity and pipe diameter are proposed. The variation law of temperature field in the heat storage pit under the condition of heat storage is analyzed. The heat storage process of the heat storage pit is optimized by numerical simulation. The heat storage process of the heat storage pit is optimized by numerical simulation, and the optimal model and inlet velocity parameters are proposed. It is concluded that the heat storage efficiency is positively correlated with the angle of the water pit. The heat storage efficiency of the model a3 is 15.48% higher than that of the rectangular water pit. The flow rate of the water distributor is positively correlated with the heat storage efficiency of the pit. At the flow rate of 0.2 m/s, the heat storage efficiency of the water pit is 7.21% higher than that of 0.05 m/s. It can provide reference for the practical application of the subsequent heat storage pit.