Abstract: The operation of the coal washery is confronted with the trouble of liability of coal refuse to undergo severe size degradation in water and the difficult sedimentation of fine slime in slurry water. To tackle the problem, a coal slurry water treatment improvement scheme is defined according to the theoretical analysis and existing state of plant operation. With the increase of slurry sedimentation rate and improvement of mode of addition of flocculants, the following remarkable improvement has been made in the treatment of coal slurry water: an increase of yield of coal slime from 6.10% to 8.30%; a rise of yield of clean blending coal from 5.15% to 5.80%; and the increase of yield of clean sub-coal from 1.57% to 1.80%.