This study takes MR (Magneto-rheological) brake as the research object, and studies the influence of temperature on the braking performance of MR Brake through theoretical analysis, finite element simulation and experiment.  Firstly, the braking torque model of MR Brake was established based on the theory of magnetic dipole model and the working principle of MR Brake. And the influence of temperature on MR Brake components was analyzed according to the temperature distribution and temperature rise of brake components under different working conditions.  Then, the temperature properties of the MR fluid were studied. The expressions of magnetization with respect to temperature were obtained according to the Weis molecular field theory, magnetic domain theory and Langevin function, and the expressions of volume fraction and viscosity with respect to temperature were obtained.  Finally, a MR braking torque model with temperature parameters was established, and the correctness of the theoretical model was verified by experiments.  The research results fill the gap in the theoretical model and have important significance for the research on the braking performance of MR brakes.