The friction coefficient of the brake pad is still about 0.45-0.55, which can ensure that the vehicle has good braking performance, high temperature resistance, wear resistance, stable braking, repair of the brake disc and environmental protection. Therefore, we should choose the brake pad with better quality. When the friction materials are used, the brake pad should be replaced in time, otherwise the steel plate will be contacted with the brake disc directly. Eventually, the braking effect will be lost and the brake disc will be damaged.