The magnetorheological damper converts the mechanical energy of vibration into its own thermal energy, and the thermodynamic energy is expressed as the temperature rise. In this study, according to the principle of temperature rise, the temperature rise of the magnetorheological damper is established theoretical model by using the simplified one-dimensional heat transfer model of a fluid element and the lumped parameter method under the action of sine harmonic wave motion and triangular wave motion, as well as using the finite element software COMSOL to simulate the internal temperature fields of the damper. The results show that the temperature values of the damper are different, there are high-temperature areas and low-temperature areas, and the temperature rise mainly comes from the heating of the coil. The different frequency and amplitude of the excitation signal, as well as the input current, will affect the internal temperature of the damper. The temperature rise increases with the increase of input current, amplitude, and frequency, which is verified on the built testbench for the temperature rise characteristics. The change trend of the theoretical calculated value, the simulated value, and the tested value is consistent; and there is an error within the allowable range. By comparison, the temperature rise trend is basically the same for the three methods; but, when comparing with the application of sine harmonic wave motion, the temperature rise of the magnetorheological damper is 5°C higher than the triangular wave motion under the same operating condition.