Aim to the question about how to integrate different information and knowledge during applying CAx systems, the architecture of CAx integrated system based on knowledge for auto drive axle was proposed. A method of similar case retrieval of measurement of feature parameters was proposed by adopting knowledge description based on ontology, and knowledge was reused. The key technologies of the system , such as case based reasoning, knowledge drive design of auto drive axle face design flow, method of CAD modeling based on feature parameters, CAE analysis based on model sharing, and virtual assembly were studied. The system platform was developed, and the integration of CAD/CAE cab be carried out based on knowledge. With the platform, design of auto drive axle was helped efficiently.