The cleaning agent determines the depth and sensitivity of the cleaning. The depth is the selection and usage method of the cleaning agent, and the sensitivity is the cleaning effect of the ultrasonic cleaner. First, try to learn as much as possible about the physical properties of the cleaning agent. It can greatly enhance the cleaning efficiency of ultrasonic cleaning machines. For instance, cleaning agents with low viscosity are suitable for gap cleaning. Those with lower boiling points have more evaporation losses, but they are suitable for steam cleaning. Choosing the appropriate temperature based on different cleaning agents has a significant impact on the cleaning effect, etc. Second, the cleaning agent of the ultrasonic cleaner can be recycled. This cleaning method can save a large amount of cleaning agents. After each use of the ultrasonic cleaner, it is best to put the cleaning agent in a container and pour it into the cleaning tank when using it next time. The remaining sediment can be disposed of. If the concentration of the cleaning agent is insufficient, just add a little and it can be reused. Iii. Waste Liquid Treatment Issues. Take water-based cleaning agents as an example. Since the waste liquid after cleaning by ultrasonic cleaning machines contains grease, dirt, sand, carbon deposits, metal shavings and polar oxides, etc., the water quality does not meet the discharge standards and should be treated. General treatment can be divided into three steps:  
        1. Use physical methods for sedimentation, standing still and filtration to remove suspended solids, floating oil and sediment.

      2. Demulsification of oil, salting out, coagulation, air flotation and electrolysis are combined to achieve oil separation.

      3. Wastewater purification can be achieved by biochemical methods, ozone method, sand filtration and activated carbon adsorption method, etc.

          The wastewater treated by the three-stage process can meet the national wastewater discharge standards.