Abstract: The coal washing operation of Xinqiao Coal Preparation Plant is directly affected by the continuous worsening of the performance of its slurry water treatment system due to wide variation of the property of the plant′s raw coal feed. To reverse this situation, apart from making study and analysis on flotation feed property and reagent, as well as promotion of slurry settlement through the use of flocculant, the following measures are adopted: adjustment of production organization; less generation of fine coal in coal washing process; change of proportioning of reagents; realization of low-density high-efficiency flotation; and optimization of types of flocculating agents and their adding mode and amount, for realizing rapid settling of slurry. Through the improvements made, the slurry water treatment system is now working well in performance in various aspects.