In order to improve the shear force of a new metal foam Magnetorheological (MR) fluid damper,based on finite element simulation software of ANSYS,the parameters of metal foam MR fluid damper were optimized by taking the magnetic field density in the shear gap as the optimal object,and taking the structural parameters of the damper including the piston working length and diameter,the cylinder wall thickness as the optimal parameters.The test device of shear force of the metal foam MR fluid damper was built,and the performance of the damper before and after optimization was compared.The result shows that the shear force of the damper after optimization is improved by 146 times,the effect of optimization of the structure parameters of the metal foam of MR fluid damper is obvious.