Abstract: The mathematic description of data exchange is presented, and then the direct and indirect data exchanges among heterogeneous CAX tools are described, based on the analysis of the data features in product collaborative simulation. Then the data exchange strategy in collaborative simulation is proposed, XML is used to exchange non-product model data which have good structure, and XML combined STEP is used to exchange non-structural product model data. The application in collaborative simulation of the powertrain system is taken as an example which verifies that this strategy is very effective.