Abstract: A coal slime continuous classifier is developed according to hydraulic classification principle. The classifier is used for making pre-classification of coal slime in a continuous manner for making it possible to carry out fine processing of various size fractions according to their respective properties. Fluent software is used to simulate the flow and velocity distribution in the classifier with the flow-regulating pipe bundles arranged in square and orthohexagonal forms, for optimum selection of the shape of pipe bundles. Test on the efficiency of the classifier is conducted in laboratory and through simulation with Fluent software, and the results obtained in both cases are in good agreement, well demonstrating the applicability of computational fluid dynamics (CFD) in research of hydroclassification of coal slime. Experimental study shows that: the ultrafine coal tends to have a higher misplacement rate as the effect of its classification is affected by external factors; and the efficiency of classification of finer size fractions needs to be further enhanced.