Compared with the conventional coaxial magnetic gear (CMG), the eccentric harmonic magnetic gear (EHMG) is more suitable for higher transmission ratio occasions. Meanwhile，in order to further augment the torque density, a novel EHMG with inhomogeneous structure and Halbach array is proposed in this paper. A fan-shaped structure is applied to the permanent magnets (PMs) on the rotor, and the PMs on the stator are unevenly divided according to the ratio of 1:n:1. In addition, both the rotor and the stator PMs are magnetized by the Halbach array. A finite element model of this proposed EHMG is established, and both the air-gap magnetic field and torque of the EHMG are calculated. Compared with the conventional EHMG, the torque of the proposed EHMG is increased from 38.04N·m to 50.41N·m, which verifies that the model is an effective attempt to augment the torque density of EHMG.