According to the coupling problem of disturbance torque and magnetic circuit during deflection of the magnetic bearing,a spherical decoupling permanent-magnet biased magnetic bearing was proposed.Based on the Maxwell equation and equivalent magnetic circuit method,the force decoupling and magnetic flux decoupling of magnetic bearing were analyzed,and the theoretical analysis results were verified by finite element simulation.The results show that the interference torque of the spherical magnetic bearing was 1.3% that of the cylindrical magnetic bearing when the rotor reaches the maximum deflection angle of 0.5°;at the middle position of the bearing radial non-magnetic block,the air gap flux density is approximately equal to 0.01 T,and the magnetic flux hardly passes through the bearing stator and rotor.By using the spherical decoupling permanent magnet bias magnetic bearing,the interference torque can be reduced,the decoupling of the magnetic flux can be realized,and the accuracy of the control torque can be improved,so it can be used as the active high-precision control of the magnetically suspended flywheel.