Abstract: Pre-classification is beneficial for slurry processing such as avoiding the repetitive treatment of coarse particles, enhancing the flotation efficiency of fine particles, and improving the concentration efficiency and pressure filtration efficiency of ultrafine particles.Based on the theory of hindered settling, the slurry classification pond was designed.Applying computational fluid dynamics method, the classification efficiencies and particle paths of every grade were calculated and simulated to reveal the motion law and classification mechanism.Hence the results show that the miscellany rates of 0.500-0.250, 0.250-0.125, 0.125-0.075, 0.075-0.045 and < 0.045 mm fractions respectively are 0, 0, 2.08%, 50.00% and 29.90%.In comparison with the simulation experiments, the results of the laboratory experiments respectively are 0, 0, 3.31%, 30.06% and 30.06%.The laboratory experimental results agree with the simulation results, and there is no doubt that slurry can be effectively classified by the slurry classification pond.