The work presents a knowledge-based engineering (KBE) methodology for ship hull structural member design. In the ship design process, many design tasks need the expertise or design experiences to support them. However, the ship design procedure is a complicated process with many labor-intensive activities. Therefore it is necessary to integrate intelligent design process into ship design. An application developed in a KBE system takes design requirements, applies the knowledge stored in the knowledge base and generates a new design automatically. Knowledge-based engineering methods for ship design are put forward, which combine with the theory of intelligent design. A ship deck design case illustrates the feasibility of the proposed approach. The KBE technology provides appropriate suggestions and support, integrates the information, to avoid conflict and errors. Besides, it also achieves knowledge reuse and accumulation, provides reliable technical support for ship design quality, significantly reduces the design cycle, and promotes working efficiency.