In order to solve the problem of low torque of magnetorheological fluid transmission device and performance deterioration of magnetorheological fluid when temperature rises, a combined transmission device of magnetorheological fluid and electromagnetic friction was proposed and the working principle of the transmission device was introduced. Maxwell software was used to perform finite element analysis of the magnetic field of the device, and the magnetic field intensity and magnetic induction intensity in the magnetorheological fluid working area were obtained when the coil was at different positions; based on the torque formula of the cylindrical magnetorheological fluid transmission device and the electromagnetic attraction formula, the torque transmitted by the magnetorheological fluid and the electromagnetic friction torque were calculated. The research results show that as the coil distribution position is closer to the friction disk, the transmission torque of the device is greater; when the coils are distributed on the outermost sides of the two ends of the driving shaft and is 0 mm away from the friction disc, the electromagnetic friction torque reaches the maximum value of 96.86 N·m, the magnetorheological fluid transmission torque also reaches the maximum value of 36.60 N·m, and the total transmission torque reaches 130.25 N·m; compared with a single magnetorheological fluid transmission, the transmission torque performance of the combined electromagnetic friction and magnetorheological transmission device is improved by 255%.