Abstract： Aimed at the inertial impact of the crane slewing mechanism brake, a kind of magnetorheological elastomers shaft device was proposed to control the vibration frequency and amplitude of impact. Dynamics equations considering the backlash, time varying meshing stiffness and nonlinear stiffness and damping coefficient of magnetorheological elastomers were established based on the working characteristics of the slewing mechanism, and the function relation between the key parameters and the electric current was deduced. The numerical solutions to equations were obtained, and the coupling torque characteristics and damping characteristics as well as the gear meshing force and braking effect were analyzed. The results show that the magnetorheological elastomer based coupling has a strong power transmission capability. It does not affect the braking effect but it can significantly reduce the shock oscillation frequency. In addition, it can inhibit the impact load peaks.