The invention discloses a matching device and matching method for an ultrasonic power supply. The matching device for the ultrasonic power supply comprises an ultrasonic
signal generator, a drive isolation circuit, an ultrasonic power amplification circuit, a matching
transformer, a tuning
inductor, an ultrasonic
transducer, a
voltage sampling circuit, a current sampling circuit, a filtering and shaping circuit, a phase
discriminator, an A / D converter, a single-
chip microcomputer and a stepping motor. The output end of the matching
transformer is connected with the tuning
inductor; the output end of the tuning
inductor is connected with the ultrasonic
transducer; the
voltage sampling circuit is used for collecting real-time working
voltage signals at the two ends of a unit formed by the tuning inductor and the ultrasonic
transducer, and transmitting the real-time working voltage signals to the phase
discriminator. According to the matching device and matching method for the ultrasonic power supply, static
impedance matching and
dynamic impedance matching can be achieved, the matching
inductance value can be tracked and adjusted through the
phase difference of working currents and working voltages of the ultrasonic transducer, it can be ensured that the ultrasonic transducer always works at a
resonance point, the maximum useful
power output of the ultrasonic transducer can be achieved, in addition, the adjusting response speed is high, and accuracy is high.