Abstract: For a heavy medium coal preparation plant,the stability of circulating medium suspension exerts a great impact on the quality of products,and it is found that the stability of the medium suspension is largely governed by the content of coal slime in suspension. In order to maintain the stability of medium suspension,it is usually required to make a divided flow of the suspension for reducing the amount of coal slime contained in it. Based on the result of study made on the splitting effect and split flow calculation,the paper presents a brief account of the causes for the appearance of "false density"and the countermeasures in field operation,and elaborates on the layout and selection of the splitter box,so as to provide some reference helpful to the management of splitting of medium suspension in plant.