Abstract: In resent years,with the expansion of scale of production of coal mine and coal preparation plant,variation of coal type washed,and constantly changing of production mode,the new issues relate to the crushed particle size of coal encountered in the processes of design and production of coal preparation,some of the issues even serious influenced the normal operation of coal separation production.This paper accordance with production practice,detailed described the necessity of control of coal particle size and the technological approach of particle size,which provides the useful ideas for design of coal preparation and production management in site.