: In order to better protect the safety of bridge piers and ships, a step-by-step progressive high energy consumption anti-collision magnetorheological damper for bridge piers was designed for the problems of passive energy dissipation, poor dynamic response and anti-collision energy dissipation, and limited adaptability of the device. The results show that: the structural parameters of the damper are established through the establishment of a mechanical model; the structural strength and magnetic circuit are analyzed using finite elements, and the strength of the damper structural components and the magnetic circuit design meet the requirements; three pistons are set up in the cylinder barrel, which can work together to divide the energy dissipation of the damper into three phases under different crash depth displacements, and the stiffness of the device is increased, which effectively improves the force of the damper and achieves the graded progressive energy dissipation of the device. The excellent effect of progressive impact energy dissipation can be realized by applying it in the bridge pier collision avoidance device, which can realize semi-active collision avoidance energy dissipation. The theoretical and finite element simulation results basically coincide with each other, proving the rationality of the damper design.