A new kind of valve push rod mechanism of fuel regulator based on ultrasonic motors is proposed. The machine is connect to the output shaft of Traveling-wave Rotary Ultrasonic Motor(TRUM) by a ballscrew, by which the circumnutation of the motor is transformed into the rectilinear motion of the valve push rod.The regulation of accelerograph is controlled by step drive of the TRUM, which is carried out by controlling the numbers of the impulse signals created by the PSoC. Some improvements of airproof capability for TRUM are put forward according to the working condition to meet the practical oil pressure. A mathematical model is founded and dynamic analysis is carried out. The experiment results come in accord with the academic analysis. The experiments prove that the design requirement has been achieved and a nanoscale positioning accuracy can be realized.