Abstract: The hydrocyclone classification is stochastic, complicated and the feed material is varied. It is important to simulate the hydrocyclone classification accurately. Anew method to simulate the hydrocyclone classification was developed in this paper for overcoming the shortcomings of theoretical and empirical simulating method. This method combined the Black Box theory and the similarity priciple is named the similarity simulation method in this paper. The hydrocyclone classification simulator was developed through hydrocyclone classification test with the method mentioned above. This simulator can represent the hydrocyclone classification and can be used for process analysis, prediction, scale-up and optimization.