Aiming at unknown attribute weights and attribute values which are expressed in trapezoidal intuitionistic fuzzy numbers, a gray relation projection pursuit dynamic cluster method is proposed. This method improves grey correlation projection method(GRPM) under the comprehensive consideration of preferential membership and grey correlation, combines projection pursuit dynamic cluster(PPDC) method and the grey relation projection method, and constructs the projection objective function. The firefly algorithm(FA) is adopted to optimize the objective function of projection for obtaining the best projection direction of grey correlation projection values, and the grey correlation projection values are evaluated, which are applied to classify, rank and prefer the alternatives. Results of the application examples verify the effectiveness and feasibility of the proposed method.