To improve the output performance of the traveling wave type rotary ultrasonic motor (TRUM) under extreme temperature environments, this paper analyzes the impact of high and low temperature environments to TRUM and its driving and controlling section. The TRUM servo control system based on MSP 430 MCU is established and realized in communication between PC and the controller via RS232 asynchronous serial port, as well as the controller and the UMD-3 type driver. The precise speed and the position control of TRUM are realized in the systemthrough the proportional-plus-step approximation control method. The experiment at－40～ 70℃ is finished.Results show that when the motor is no-load, the maximum speed increases and then decreaseds as the temperature increases, and the peaking value is between ±10℃. Compared with the measured maximum value, it decreases by 43.2％ and 12.6％ at 70℃ and -40℃. This systemp ositioning accuracy is 0.1°, and the speed control accuracy is 1 r／min inthe adjustable range. Results show that the certain position and the speed accuracy of TRUM can be achieved by servo control method.