The front and rear ends of the car are equipped with bumpers, which not only have decorative functions, but also are safety devices that absorb and mitigate external impact forces, protect the body and protect the body and occupant safety functions. The bumper has the functions of safety protection, decorating the vehicle and improving the aerodynamic characteristics of the vehicle. From the safety point of view, when a car has a low-speed collision accident, it can play a buffering role to protect the front and rear body; it can play a role in protecting pedestrians in the event of an accident with pedestrians. From the appearance, it is decorative and has become an important part of the decoration of the car. At the same time, the car bumper has a certain aerodynamic effect.