Under the background of the current global energy transition and environmental protection, the development of new energy vehicles has become a global hot spot. As one of the key technologies of new energy vehicles, the electric wheel drive system has gradually become the key to the development of electric vehicles because of its high integration and high-power density. In this paper, the temperature rise and thermal deformation of the key components of the electric wheel under the compound braking condition are studied. Firstly, the geometric modeling and parameter setting of the electric wheel are carried out, and then the temperature field and thermal deformation under the joint action of friction brake and hub motor are simulated based on ABAQUS finite element analysis software. The results show that the temperature rise of the brake disc decreases under composite braking, and the temperature rise of the motor is mainly caused by the braking loss of the motor itself, in which the temperature rise of the permanent magnet is the highest. In terms of deformation, the deformation of the brake disc is the most significant, while the deformation of the motor part is relatively small and can be ignored.