The field test and simulation analysis are accomplished to analyze the impact of oil temperature on inherent dynamic performance of yaw damper and vehicle dynamic performance. The test results show that the energy absorbed by yaw damper, the dynamic damping and stiffness of damper increases as the temperature decreases in the proper range of oil temperature, while decreases as the temperature decreases when it exceeds the proper range of oil temperature. The simulation results show that the critical hunting speed increases as the temperature decreases in the proper range of oil temperature, while decreases as the temperature decreases when it exceeds the proper range of oil temperature. Moreover, there is not obvious effect of the oil temperature of the yaw damper on vehicle stability and safety.