An axial sectional claw pole high speed square wave motor with permanent magnet outer rotor was proposed and designed which was applied in axial air compressor group to realize direct drive. Firstly, according to the core loss in high speed motor is greater, a new calculation model was built to compute core loss accurately by a way of equivalent substitution three orthogonal alternation magnetization for approximate rotation magnetization. And the calculation results are consistent to the finite element results. Furthermore, for a high-speed machine the air friction loss of its rotor surface is much greater than that of a traditional one. The influencing factors, such as rotor speed, surface roughness and axial wind speed were analyzed in this paper. It has a certain reference value in the application of soft magnetic compound materials (SMC) and the optimal design and the analysis of high-speed claw pole motor.