The invention discloses a novel magnetorheological damper comprising an outer cylinder, a rotor cylinder located in the outer cylinder and a ball lead screw located in the rotor cylinder. One end of the ball lead screw stretches out of the outer cylinder, and a compression buffering block and a connecting screw rod are installed at the end of the ball lead screw, and meanwhile, the ball lead screw is further sleeved with a ball nut and a nut seat; the nut seat is fixedly connected with the top end of the rotor cylinder; the bottom end of the rotor cylinder penetrates through an upper partitioning plate, an outer stator and an inner stator and is connected with a rotor; the rotor cylinder and the rotor are supported on a pair of angular contact ball bearings to conduct rotating motion; the upper partitioning plate, the outer stator, the inner stator and the rotor form a closed chamber; the chamber is filled with magnetorheological fluids; two annular grooves are formed in the inner stator; coils are wound in the two annular grooves correspondingly; and two magnetic fields are produced after the coils are electrified. The novel magnetorheological damper has performance that the magnetorheological fluids are small in using amount, the damping is high , and the high damping is achieved even at a low frequency, the smoothness of a vehicle can be improved, and the control stability of the vehicle can be also controlled.