The present invention provides a resonance ultrasonic transducer. The resonance ultrasonic transducer comprises an ultrasound source for transmitting ultrasound, and a reflecting unit disposed opposite to the ultrasound source. The ultrasound source and the reflecting unit Constitute a resonance cavity. The reflecting unit can also act as an ultrasound source. A specific distribution of the acoustic field may be formed in the resonance cavity by matching the transmitting acoustic field of one ultrasonic transducer with the reflecting acoustic field of the other ultrasonic transducer. This resonance ultrasonic transducer can be widely used in ultrasonic diagnosis device, ultrasonic therapy device and ultrasonic detection devices and carries out effective focusing and controlling of an ultrasonic fled.