This paper aims to investigate the effect of temperature on the transmission characteristics of high-torque magnetorheological (MR) brakes by theoretically analyzing a disc brake, the pressure characteristics of the magnetorheological fluid (MRF) in axial, and the heat dissipation of an MR brake. A high-torque squeezing MRF brake with a water cooling method for heat dissipation is designed and a temperature-torque performance experimental system is established to conduct the experiments. The experimental results indicate that the high-torque squeezing MRF brake exhibits workable pressure characteristics. Meanwhile, the braking torque presents a variation trend that is initially increasing then decreasing when the temperature increases from 25 °C to 150 °C. The magnitude of decrease is approximately 210 N m, which decreases from 1800 to 1590 N m. Moreover, the temperature of the MRF presents an almost linear increase at different slip powers and the rate of temperature rise increases with an increase in slip power. The findings of this study prove that an effective cooling method can be vital to the stable operation of the high-torque MR brakes.