Abstract: According to some problems about the maintenance difficulties through point-to-point integration，a bi-directional integrated solution based on MIP（Middle Integrated Platform） between CAD and PDM systems is proposed，including business process modeling of bi-directional integration，data forms of the BOM（Bill of Material） and associated drawing documents in CAD/PDM，CAD/PDM data integration model based on MIP，embedded adapters，XML data exchange protocols，message systems，as well as the adapter embedded software development with the message systems.Finally，the validity of this method is demonstrated via a case study of jig’s design exchange data.The application result shows that this solution has a good flexibility and expansibility，and can realize bi-directional data accessing and exchanging between CAD and PDM systems.