Abstract: A hybrid finite element (FE) and double air-gap macro elements method is proposed to solve the magnetic fields for magnetic harmonic gears. The non-uniform air-gap region was divided into three layers in the model. The two-uniform air-gap layers, connected to the stator and the rotor respectively, were treated by the macro air-gap elements. The non-uniform middle air-gap layer as well as the stator and the rotor, were discretized by FEs. Not only could the non-linear properties of the ferromagnetic material be taken into account but also the motion of the eccentric rotor could be easily handled. The equivalent motion mode and the sliding surface technique made the calculation of the air gap coefficients only once. The magnetic fields and the torque were computed by the proposed approach for a double stage magnetic harmonic gear prototype. Finally, torque measurements of the prototype were presented to confirm the validity of the prediction of the proposed method.