Based on the coal medium and small particle size composition is increased significantly, the slime water treatment capacity is obviously insufficient, the circulating water quality deterioration ,affect the coal preparation plant in quantity and quality problems, Yunjialing mine coal washery of dosing system, φ30m thickener, coarse slime recovery system and water circulation system has carried on the technological transformation.Practice shows that after the implementation of technological transformation of the coal slime water treatment system, washing capacity significantly increased, up into the coal quantity of per hour by former transformation of 230t to 300t, realized the full into the raw coal washing. After concentration underflow concentration control in about 400 g/L, fully meet the requirements of the filter press into the material, the filter press with a single cycle production time of 45 min to 30 min, polyacrylamide usage month save 450 kg, about 5 t per hour of coarse coal slime, created a considerable economic benefits.