Abstract: Aiming at the state monitoring of manufacturing process and equipment, the paper presents the representation method of monitoring object's fuzzy quantity space.The paper then puts forwards a consistent problem solving technique .The consistency-identifying algorithm is discussed by adopting fuzzy set theory and defining the degree of decision similarity, and the consistent problem solving algorithm is designed by translating the consistent problem solving into the fuzzy opinion aggregation of several experts' estimates represented by trapezoidal fuzzy numbers in group decision-making environment. Finally the method is applied to the state monitoring application of FMS, whose availability and feasibility are testified.