The invention discloses a novel unidirectional speed bump convenient for damping; the speed bump comprises an arc speed bump which is arranged on a road; an installing board is fixed on the road; a T-shaped chute which has the same shape with the speed bump is installed at the inner side of the speed bump; an installing groove is installed on the road under the speed bump; a support rod is vertically arranged inside the installing groove; one side of the speed bump is connected with the installing board through a rotating shaft; a T-shaped slide block which is slidingly cooperated with the T-shaped chute on an upper end of the support rod; a spring is installed at a lower segment; the other end of the spring is installed on a pedestal plate of the installing groove bottom for connecting. The present invention can perform unidirectional deceleration on a vehicle traveling on a one-way road or on a traffic control road, and can prevent the vehicle from going backward. At the same time, during the process of decelerating the vehicle, the vibration caused by the speed bump can be reduced, and the comfort of the vehicle passing through the deceleration belt can be improved.