Knowledge has become a key economic resource of enterprise and to become even only source of competitive advantage. With the structure of the product more and more complicated, function more and more incline to integration and compounding, modern product design is one base on knowledge. Knowledge-based integrated information system, to support knowledge management and technology innovation, is the development trends of information integration system. The integration information of computer aided technology (CAx) was analysed. A data structure of integration product model base on relation database was introduced. Knowledge-based integration system for product development was drawn out. It is a system base on product data management system and knowledge management system. This system framework used synthetically information technology and advanced manufacture technique, and realized product speedy and innovation design.