YKS series highvoltage and highspeed motor had the characteristics of high single unit capacity and large local temperature rise. A YKS5602 3 000 kW highvoltage and highspeed motor was taken as an example. According to the actual size of the motor, the motor end winding and statorrotor models were established. The finite element method was used to simulate the fluid field and temperature field. The flow of cooling gas in each ventilation slot was calculated during motor operation. The fluidsolid coupling analysis of the whole motor was carried out to obtain the temperature field distribution of the end winding and stator of the highvoltage motor. The simulation results were analyzed and compared with the experimental data. The results showed that the method of coupling the fluid field and temperature field could accurately acquire the gas flow in each ventilation slot of the YKS motor and the local temperature rise distribution in the motor.