This paper provides one kind of knowledge construction to let the engineers and technicians apply the knowledge to the product’s simulation optimization function, the ability of establishing the design criterion and the technical standard, and the convenient knowledge reuse tool to manage the knowledge effectively. In this paper the knowledge expression, the knowledge tool as well as the inference engine of the knowledge library is packed as the knowledge management module which is called for the design simulation optimization system of the outside products. The application frame of the knowledge module takes the knowledge management as a center, and form finally the knowledge management engine embedded in the design simulation system based on the unified multi-disciplinary modeling. Therefore, the knowledge management module is divided into the knowledge modeling, the knowledge expression, the knowledge reasoning, and the knowledge management. Aiming at the deep custom-made degree of the multi-functional hydraulic lift machinery, the complex restraint and coupling relations between the components and parts, the non-unified model descriptions between the multi-disciplines, and the difficult management of massive isomerous data, the basic frame of the multi-disciplinary configuration optimization design for the ETO product of the hydraulic lift machinery is proposed in the paper.