Abstract: In view of the poor data integration and the inadequate data application in the AIT process of spacecraft, this paper, by means of the data modeling and the data integration, studies the evolution process of the AIT process data of the product structure, the time cycle and the development stage. A multidimensional data model is constructed, and a multidimensional data management system is developed based on the product structure. The system, with the product structure as the core, restructures the AIT process data by defining the correlations between different systems and data of different dimensions, to realize the structured integration of the whole data of th AIT process. The AIT process data package is then built on this basis.