The study shows: the role of ultrasound in the liquid, the liquid in each bubble burst moment will produce tremendous shock wave energy, equivalent to instantly generate hundreds of degrees of heat and up to thousands of atmospheres, this phenomenon is called " cavitation ", ultrasonic cleaning is the bubble burst with a shock wave generated by the liquid to achieve the role of internal and external cleaning and scouring the surface of the workpiece. Ultrasonic propagation in liquid, the liquid together with the cleaning tank at ultrasonic frequency vibrations, liquid cleaning tank and has its own natural frequency of vibration, the vibration frequency of the acoustic frequency, so people can hear the hum. Ultrasound is a mechanical vibration frequency is higher than the acoustic wave, the wafer by a transducer excitation voltage occurs at the vibration, it has a high frequency, wave length, small diffraction phenomenon, especially good directivity, can become rays directed propagation characteristics. Ultrasonic liquid, solid penetration ability is significant, particularly in the sun opaque solid, it can penetrate a depth of tens of meters. Ultrasonic encountered impurities or interface will have a significant reflection is reflected as an echo, hit moving objects can produce Doppler effect. So ultrasonic testing is widely used in industrial, defense, biomedical and so on. Ultrasonic cleaning machine uses the principle of ultrasonic cleaning, you can reach a comprehensive clean cleaning effect object, especially for deep, blind holes, bump tank cleaning is the best equipment, material and does not affect the accuracy of any thing. Meanwhile in biochemistry, physics, chemistry, medicine, research and tertiary institutions can be used for the extraction experiments, degassing, mixing, crushing cells, nano decomposition purposes.