The hub motor often has a high temperature rise due to the narrow working space and the untimely heat dissipation caused by the loss, which affects the working efficiency of the motor. Aiming at this problem, the temperature rise characteristics and thermal deformation of the hub motor are analyzed. Firstly, a V-type permanent magnet vernier motor with outer rotor is proposed. It is calculated how much the motor will lose under various working situations, and the temperature rise of the motor under different working conditions is analyzed. Through the thermal-solid coupling method, the motor deformation of the motor after a period of rated work is observed. Finally, a permanent magnet motor prototype is used for temperature rise test to verify the accuracy of the temperature field analysis method. The experimental findings demonstrate that the mistake between the temperature rise test and the simulation experiment is 3.8 %, which can prove the accuracy of the magneto-thermal two-way coupling test method.