The rational design of the components of the electric vehicle braking system plays a crucial role in impro-ving the braking performance of the vehicle and enhancing the driving safety of the vehicle.This paper mainly analyzes the structure,function and work requirements of the disc brake system for small electric vehicles.In this paper,the pa-rameters and structure design of disc brake for small electric vehicle are made by using the theory of automobile and parts design and the correlation parameters of braking system.This paper first uses the Pro/e three-dimensional modeling soft-ware to model,to determine the design small electric vehicle disc brake's structure rationality.