In order to improve the braking performance of magnetorheological (MR) brake, a new MR brake with parallel multi-channel structure was developed in this paper. The three layers of axial damping gaps in the MR brake were utilized by using of the magnetic conductivity of the material, and the double excitation coils was also adopted to effectively improve the braking performance. The braking torque and temperature characteristics were analyzed theoretically, and the electromagnetic field and temperature field were simulated and verified. Braking performance and temperature characteristics of the parallel multi-channel MR brake were tested, and the torque, braking time and temperature characteristics of the MR brake were obtained. The test results show that under the condition of constant rotational speed of 700 r/min and applied current of 2 A, the maximum torque can reach 26.25 N⋅m, and the temperature rises from 18.3 °C to 58.01 °C within 20 s. Meanwhile, the braking time is about 1.63 s.