Basic working principle: ultrasonic screening system is composed of ultrasonic resonant power supply, oscillator and resonance ring. The high frequency electric oscillation generated by the ultrasonic resonant power supply is converted into high frequency sinusoidal longitudinal oscillation wave by the oscillator. These oscillation waves are transmitted to the resonance ring to generate resonance, and then the vibration is evenly transmitted to the screen surface by the resonance ring. The material on the screen is doing low-frequency three-dimensional vibration at the same time, superimposed on the ultrasonic vibration, not only can prevent mesh clogging, but also can improve the output and quality of screening