1. Mechanical effect: the mechanical effect of ultrasonic can promote the emulsification of liquid, the liquefaction of gel and the dispersion of solid. When standing waves are formed in ultrasonic fluid media, tiny particles suspended in the fluid condense at the nodes due to mechanical forces, forming periodic accumulations in space. The induced polarization and magnetization caused by the mechanical action of ultrasonic waves during propagation in piezoelectric and magnetostrictive materials.

2. Cavitation effect: Ultrasonic waves can generate a large number of small bubbles when applied to liquids. One reason is that local tensile stress occurs inside the liquid, forming negative pressure. The decrease in pressure causes the gas originally dissolved in the liquid to become supersaturated and escape from the liquid, becoming small bubbles. Another reason is that strong tensile stress tears apart the liquid into a cavity, known as cavitation. The cavity contains liquid vapor or another gas dissolved in the liquid, and may even be a vacuum. Small bubbles formed by cavitation will continuously move, grow, or suddenly burst with the vibration of the surrounding medium. When it bursts, the surrounding liquid suddenly rushes into the bubble, producing high temperature, high pressure, and a shock wave. The internal friction associated with cavitation can form charges and generate luminescence within the bubble due to discharge. The technology of ultrasonic treatment in liquids is mostly related to cavitation.

3. Thermal effect: Due to the high frequency and energy of ultrasound, it can produce significant thermal effects when absorbed by the medium.

4. Chemical effects: The action of ultrasound can promote or accelerate certain chemical reactions. Pure distilled water produces hydrogen peroxide after ultrasonic treatment; Nitrous acid is produced after ultrasonic treatment of water containing nitrogen gas; The aqueous solution of dye will change color or fade after ultrasonic treatment. The occurrence of these phenomena is always accompanied by cavitation. Ultrasonic waves can also accelerate the hydrolysis, decomposition, and polymerization processes of many chemical substances. Ultrasonic waves also have a significant impact on photochemical and electrochemical processes. After ultrasonic treatment, the characteristic absorption spectral bands of various amino acids and other organic substances in aqueous solutions disappear and show uniform general absorption, indicating that cavitation has altered the molecular structure.