In order to design a driver of piezoelectric ultrasonic transducer which can provide high quality ultrasonic signal and be able to realize the frequency tracking rapidly, accurately and intelligently during the bonding process, the ATmega128 microcontroller and AD9851 synthesizer are selected as core components to build an ultrasonic generator and frequency tracking system. The basic circuit units including low pass filter, power amplifier, signal detection and conversion circuits are also established. The test results of the system shows that, based on DDS technology, high quality ultrasonic signal for transducer can be achieved. By combining the two kinds of frequency tracking methods, the system can realize the frequency tracking during the bonding process. It also indicates that the design significantly improve the precision and flexibility of the ultrasonic generator system.