The development of electric vehicles (EV) is constrained by factors such as the spatial distribution and planning volume of charging infrastructure. In order to determine the planning volume of charging piles in charging stations and the spatial layout of charging infrastructure service area within the service radius of Tianjin, this paper firstly determines the service area demand based on the service radius, combined with the demand prediction function and the EV ownership, and secondly forms the charging infrastructure service area with the central place theory large spatial layout, and finally determine the planning volume of charging infrastructure through queuing service system. The research results can provide a new theoretical basis for the layout planning of charging infrastructure, and finally put forward the relevant factors and development trends for the optimal layout of charging facilities.