In order to improve the economics of electric vehicle charging stations, it is necessary to reasonably configure the charging station capacity in conjunction with the energy storage system. By investigating the actual charging data of electric vehicles and analyzing the load characteristics of charging stations, it is known that different sizes of charging stations should be equipped with different capacities of energy storage systems. Utilizing the penalty factor and taking the annual net income of the charging station as the optimization target, the capacity allocation model of the charging station is established separately with and without the energy storage configuration, and the mathematical method is used to solve it. Finally, a simulation example is carried out at a charging station to verify the effectiveness of the proposed configuration model.