This paper introduces and ana ly zes the circu la ting cha racte ristics of con tro l and ope ratingm ode o f c ircu la-t ing flu idized bed bo iler and the character istics of the contro l sy stem, expounds in de tail the contro l stra tegy o f a fuzzy expert control sy stem for combustion o f circu la ting flu id ized bed bo iler and the system used to con figurate DCS JX- 300X, and desc ribes the contro l e ffect and operating reliability of the expert contro l system after the system is applied to the burn ing proceeding of 75 t/h c irculating fluidized bed boile r