Abstract: To realize the data exchange of 3D model of satellite parts and components between CAD system(Pro/E) and CAM system(UG), IGES and STEP standards are studied in the paper according to the mechanism of data exchange between systems. Based on the study, the data transition experiment is made and compared in the standards IGES and STEP. The method of model data exchange between Pro/E and UG has been put forward based on STEP standard.