The mechanism of ultrasonic cleaning is to make use of the physical effects such as cavitation, radiation pressure and sound flow in the cleaning liquid. It can exfoliate the machinery produced by the dirt on the cleaning parts, and can also promote the chemical reaction between the cleaning liquid and the dirt, so as to achieve the purpose of cleaning the object. The frequency of the ultrasonic cleaning machine can be selected by 10~500 kHz according to the size and purpose of the cleaning material, generally more than 20~50 kHz. With the increase of the frequency of the ultrasonic transducer, Langerhans oscillator, longitudinal oscillator and thickness oscillator can be used. In the miniaturization aspect, radial vibration and flexural vibration are also adopted. Ultrasonic cleaning has become more and more widely used in various industries, agriculture, household equipment, electronics, automobile, rubber, printing, aircraft, food, hospital and medical research.