The bumper can protect the vehicle, decorate the vehicle and improve the aerodynamic characteristics of the vehicle. From the safety point of view, the car can play a buffering role in low-speed collision accident to protect the front and rear vehicle bodies; In the accident with pedestrians can play a certain role in the protection of pedestrians. From the appearance, it is decorative and becomes an important part of the decorative vehicle appearance. At the same time, the bumper has a certain aerodynamic effect.