This paper proposes an integrated Halbach-magnetic-geared permanent-magnet (PM) motor to meet the new demands arising from electric vehicles. It can offer the advantages of lightweight, compact size and low-speed high-torque operation. The key is to newly incorporate the Halbach arrays into the coaxial magnetic gear (MG) in such a way that the PM motor field and the MG field are decoupled. In addition, because the adoption of Halbach arrays can enhance the effective harmonic components as well as suppress the useless harmonic components of the magnetic field, the torque transmission performance of the outside MG can be improved. Moreover, the iron losses can also been reduced. Simulation results based on the time-stepping finite element method are given to verify the validity of the proposal.