With the finer particle size composition of the raw coal washed into the washing and transportation of Xipang Coal Preparation Plant, the content of high ash and fine mud in the feed of the clarification of the tail coal was increased, and the grain size of -0.045 mm was even close to 90%. It was difficult to clarify the washing water. Under the premise of not implementing the large-scale renovation project, in order to alleviate the insufficient processing capacity of the existing coal slurry water clarification link equipment, with the test method, the coal slurry water clarification agent was adapted to the characteristics of the existing materials, and the clarification water agent addition mode was optimized and coordinated. The use of organic and inorganic polymer flocculants and other measures finally eased the pressure on the clarification of the coal slurry in the coal preparation plant, ensuring clean water washing and stabilizing the washing product index.