Fluid cyclone is a common separation and classification equipment, and the principle of centrifugal sedimentation is often used. When the two-phase mixture to be separated enters the hydrocyclone tangentially from the periphery of the hydrocyclone at a certain pressure, a strong three-dimensional elliptical strong rotational shear turbulent motion is produced. Because of the particle size difference between coarse particles and fine particles, they are affected by centrifugal force, centripetal buoyancy force, fluid drag force and so on. Under the action of centrifugal sedimentation, most of the coarse particles are discharged through the bottom outlet of the hydrocyclone, while most of the fine particles are discharged from the overflow pipe, so as to achieve the purpose of separation and classification.