The temperature characteristic has significant influence on the dynamic performance of magnetorheological damper, so it is of great significance to study the theoretical model of temperature rise, to analyze and improve magnetorheological damper temperature characteristic. Based on the energy balance relationship of magnetorheological damper, the temperature rise theory and heat transfer mechanism of magnetorheological damper under different motion amplitudes excitation are revealed, and the temperature rise theoretical models under small and large sinusoidal harmonic motions are established.The temperature rise rule of damper is analyzed by finite element simulation. The simulation results show that the temperature of magnetorheological fluid in the damper cavity increases to 3.2℃ with small sinusoidal harmonic motion amplitude, and the temperature of magnetorheological fluid at different positions in the damper cavity is large. The temperature of magnetorheological fluid increased by 20.8℃ during the large motion amplitude, and the temperature of magnetorheological fluid at different positions in the cavity is almost equal, the theoretical model of temperature rise of magnetorheological damper is verified. It is verified by the temperature rise characteristic test, and the temperature rise test curve is consistent with the simulation and theoretical calculation results. The theoretical model has a large error in predicting the temperature rise of magnetorheological fluid under small motion amplitude, while the predicted value is more accurate under large motion amplitude. The temperature rise theoretical model not only effectively predicts the internal temperature of the damper, but also provides a theoretical basis for the structural design and engineering application of magnetorheological damper.