In order to improve the efficiency of the direct drive system in electrical vehicles and broaden its operation range, an axial field flux-switching composite machine (AFFSCM) is proposed in this paper. AFFSCM is composed of the axial field flux-switching permanent magnet machine and the magnetic gear, and therefore it has the advantages of compact structure, high power/torque density, and wide speed regulation range. At First, the harmonic components of the inner/outer air gap flux density before and after the regulation of the rotary magnetic modulation ring (RMMR) are analyzed by the analytical method, and the coupling conditions of the inner/outer air gap magnetic field are deduced. Then, the three-dimensional finite element (FE) model of AFFSCM is built and the electromagnetic performances are analyzed by FE method, including the flux density of the inner/outer air gap, the speed and static torque of the permanent magnet rotor and the RMMR. The FE results are similar with the theoretical results，which validates the correctness of magnetic modulation mechanism.

Axial field; composite machine; finite element method; magnetic field modulation. rotary magnetic modulation ring