A driving power supply was designed for the two-degree-of-freedom (2-DOF) ultrasonic motor with a single plate-shaped vibrator. According to the heavy current burden and low power utilization of the driving power supply, a method for optimizing the driving performance was proposed. The power supply used a voltage-controlled oscillator to generate a small sine signal, and applied a high-voltage and power amplifier to produce a higher driving voltage and a larger driving current. According to equivalent circuit and operating characteristics of piezoelectric vibrator, the ultrasonic motor was connected with an appropriate inductor in parallel to optimize the driving performance of the driving power supply. A prototype of driving power supply was made and its output performance and optimization effect were tested in an experiment. Experimental results show that the control variables of ultrasonic motor in power supply-driving voltage and frequency can be adjusted independently and continuously, and an ideal waveform of sine signal is obtained. When the power supply is loaded by the 2-DOF ultrasonic motor in frequencies of 49.127 kHz and 49.756 kHz, the maximum output voltages are 176.0 V and 171.2 V. When the ultrasonic motor is connected with a 1.442 mH inductor in parallel, driving current can be reduced to 7.27% and 7.41%, and the power factor can reach 0.968 and 0.955 0, respectively. The power supply designed meets the driving requirements of the ultrasonic motor, and optimization method on reducing current burden and improving power utilization has good results.