As synchronous periodic vibration forces are induced by both uneven distributed mass and magnetic center offset when the active-passive hybrid magnetically suspended rotor rotates at high speed,this paper proposes an autobalancing method to remove the vibration forces.Firstly,the offset parameters of the passive magnetic bearing were calculated from the synchronous periodic control currents extracted in the zero-displacement control condition.Then a general notch filter was designed to inhibit the synchronous current and to obtain the synchronous displacement at the same time.After carrying out the feedforward compensations of active-passive magnetic bearing displacement stiffness force and the offset of the passive magnetic center,the synchronous period force component of the active-passive magnetic bearings was removed entirely.The method was verified by simulations and experiments,and compared with an algorism without passive magnetic center offset compensation.The simulations indicate that the synchronous force has reduced to 6% of the algorithm without passive magnetic center offset compensation.Experimental results indicate that the synchronous vibration acceleration has reduced to 23.3% of that without passive magnetic center offset compensation.Simulation and experiment results demonstrate the effectiveness of the proposed method and show that the method is effective for elimination of synchronous vibration force and realizes the automatic balance control for rotors.