Provided is a control method of a mechanical elastic energy storing permanent magnet motor group under non-harmonic disturbances. The permanent magnet motor group comprises a permanent magnet synchronous motor, a gear gearbox and a volute spring box used for mechanical elastic energy storing. The control method includes that a full system mathematical model including the permanent magnet synchronous motor, the gear gearbox and the volute spring box is constructed, and then non-linear internal model equations and a state feedback controller are designed aiming at nonlinear disturbances generated by a nonlinear external system. According to the control method, the different non-linear internal model equations are designed on the basis of type features of external disturbances, and the state feedback controller is designed on the basis of a nominal system control law. Test results prove that the designed state feedback controller can ensure that angular velocity output by the permanent magnet motor group under various external disturbances is basically stable and enables a closed loop system to fast track reference signals, and high-accuracy servo control of the motor group is achieved.