Abstract: Under the dual-carbon background, the rapid development of Electric Vehicle (EV) has well responded to the national energy intention of clean and low-carbon transformation.Electric Vehicle Charging Station (EVCS) is a necessary charging infrastructure for EV. Its reliable performance and reasonable layout planning not only affect the interests of investment operators, but also directly affect whether users travel economically and conveniently.Therefore, in order to balance the operating interests of investors, provide EV users with a good charging experience, and configure the optimal number and capacity of charging piles in the station, this paper conducted research on the problem of determining the optimal number, capacity and site. Firstly, the Monte Carlo method is used to predict the temporal and spatial distribution of charging demand and the average stopping time and average charging time of charging piles with different capacities. Then the planning model of location and volume is established, and the particle swarm optimization algorithm is used to solve the model for location optimization. Finally, taking a city as an example, the simulation experiment is carried out to obtain the optimal charging station location and capacity scheme, which verifies the effectiveness of the optimization method proposed in this paper.