On the basis of research on reasons of decision-making problems’complexity , the paper gives out an ex2 act definition of formalization of complicated decision-making problems. Then the paper puts forward a logical frame2 work for formalization method of complicated decision-making problems. The framework is composed of three parts , that is , the representation layer of complicated decision-making problems , the structurization layer of complicated decision-making problems and the integration layer of quantitative analysis models. The paper makes a profound dis2 cussion on the key problems arising in each layer