The specifi c bench test specifi ed by the product design standard is an important basis for judging whether the vehicle motor meets the requirements. To study the temperature rise characteristics of automotive permanent magnet synchronous motors under bench test conditions. Firstly, the bench condition was taken as the target we need to study, and the fi nite element method was used to calculate the loss of each part during the bench test condition. Secondly, use this loss as the heat source for temperature fi eld calculation to simulate the temperature fi eld of the motor under bench test conditions. Finally, a bench test platform was built for testing, and the test results and simulation results were compared and analyzed. Studies have shown that in the entire process of changing conditions, the temperature of each component is not the same as the sensitivity to changes in operating conditions. The maximum relative error between simulation and experiment was 9.4%, which verifi es the eff ectiveness of this research method and process, which has certain guiding signifi cance for the design and optimization of vehicle motors.