Abstract: According to the problems of the amount of original coal slime to into production system increased,the concentration of underflow and overflow of thickening pool increased in the production process in Meihuajing branch of Ningdong coal preparation plant,through strengthen production management to reduce the quantity of original slime that into the washing system,reform the adding method of flocculant and coagulant dosage and blending ratio,effectively reduced the solids content of circulating water,ensure the normal operation of the production,realized coal washing with clean water.