At present,the common measures to improve the MRB braking torque are:bettering the performance of the MRF,ameliorating the structure of brake and increasing the magnetic field intensity.In summary,the braking torque of MRB prototype is improved by changing the structure of brake,but the magnetic field has still not been fully utilized.The braking performances of coilexternalmounted MRB and coilsidemounted MRB were compared and analyzed by the combination of theoretical analysis,numerical simulation and experimental verification to obtain the influence of coil being placed on the performance of MRB.It provides reference for the development of MRB.