Abstract: Fast charging of electric vehicles can effectively solve the disadvantage of long-time charging, but it has such features as high charging power and great randomness. To solve this problem, energy storage is applied to fast charging stations for electric vehicle to alleviate the pressure of the power grid, and to enhance the stability of power grid. According to distribution of vehicle stops for traditional gas station, the Queuing Theory is used to build load model of charging station to obtain the days biggest arrival rate, then to determine the number of chargers. The chargers are divided into storage side chargers and grid side chargers, and a charging capacity allocation model is constructed. The objective of this model is to minimize investment costs of station equipment and purchase costs of electricity, so the proportion of chargers is configured. In the end, the feasibility and validity of the model are verified through an example.