Abstract: To satisfy the demands of clients participating in individuation products design, the principle scheme of design system based on B/S multi-layer structure mode is given. The key technologies involved are discussed in the aspects such as the part information model, product structure assignment model and interface class design of system integration. Finally, a prototype-system used in the gear-box individuation design is presented, with a discussion on the establishing process of the correlative models and feasibility validation of the system.