Abstract: Because the washability of feed coal in Shiban coal preparation power plant become worse,it is necessary to purchase high-quality coal for blending to improve the washability,and then a risk prevention mechanism is established for better control of purchased coal quality in the process of exploration of coal resource,contract signing,collection and preparation management,quality control etc. The practice shows that it can reflect objectively and truly the quality of purchased coal,and maintain interests to achieve a win-win between the coal preparation power plant and supplier.