For power ultrasonic piezoelectric transducers, there exists problems of matching imbalance of due to the change of working environment and load fluctuation, and the problems of low design efficiency and higher error rates in the design process on account of the complex computing process. An improved LC matching circuit based on analyzing the traditional LC matching circuit was designed by adding adjustable element to compensate matching disorders. A parametric design method for impedance matching circuit of power ultrasonic piezoelectric transducer was proposed, and corresponding parametric design software was developed. The experimental results showed that this design method and software could provide a convenient, practical, efficient and reliable design tool for the matching circuit of power ultrasonic piezoelectric transducer.