The working principle of grain cleaning machines usually includes mechanical cleaning, hydraulic cleaning, or pneumatic cleaning. Mechanical cleaning separates grains from impurities through the rotation and vibration of components such as drums and screens; Hydraulic cleaning is the use of water flow to flush the surface of grain, removing stains and impurities attached to it; Pneumatic cleaning is the process of using wind to blow away light impurities, while using components such as screens to separate large particles of impurities.

The drum cleaning machine utilizes the rotation of the drum and the scouring effect of water to remove impurities from the surface of grains. Suitable for cleaning larger grains such as rice and wheat. The wind screen cleaning machine uses wind power to blow away light impurities in grains, while using a sieve to separate large particle impurities. Suitable for cleaning beans, seeds, etc. The water jet cleaning machine uses high-pressure water flow to wash grains, which can remove soil, stains, etc. on the surface of grains. Suitable for cleaning various grains.