Magnetorheological damper (MRD) can realize controllable damping, which is used as a semicontrolled smart device in many fields.On the basis of the experiment and based on the Bingham mechanical model, mechanical model of MRF damper including linear and nonlinear are established. Each of the theoretical mathematical model was obtained after parameter identification.Due to the nonlinear polynomial model was easy to produce Runge turbulence, and the appropriate order could not be obtained by effective methods. Therefore, the nonlinear model was built by Fourier series.The linear and nonlinear models were compared with the experimental results respectively. The results show that the linear model can not accurately represent the actual characteristics of damper at a low speed with a load current.The nonlinear model based on Fourier series can exactly reflect the nonlinear response of the MRD, and the curve is basically consistent with the experimental results.The results can provide the reference of MRD dynamics model of establishment.