In order to improve the braking torque of the traditional magnetorheological brake with double coils placed on side housing,a novel magnetorheological brake with double coils ripple is proposed. The novel structure enabled it to have larger area of controllable shear face by adding semicircular grooves and ridges on the end surfaces of conventional magnetorheological brake with double coils placed on side housing. The center position of the semicircular grooves and ridges is determined by mathematical method,the torque model of the novel magnetorheological brake is derived. The results show that when the novel magnetorheological brake adopting the way of semicircular groove in the rear of ridge,and the number of semicircular grooves or ridges is two,the novel magnetorheological brake can obtained the maximum torque of 184. 6 N·m. Compared with traditional magnetorheological brake with double coils placed on side housing,the braking torque of the novel cycloid curved magnetorheological brake is increased by about 46%. The results can be taken as reference to the design of magnetorheological brake.