In this paper, the definition of satellite digital Mockup was given, and the digital Mockup was classified according to three dimensions, and the method of constructing the digital Mockup in the order of overall to detail, from high to low, from outside to inside was given. The design of satellite digital Mockup was a gradual refinement process. In order to accurately describe the state of each stage of satellite digital Mockup, the concept of maturity was introduced, and the order and rules of model evolution were given according to the maturity of digital Mockup. The application scope of the digital Mockup was given, and the emphasis was laid on the partition optimization design. Through the study of definition of digital mockup and application of zoning optimization, to adopt digital technology in satellite development can improve the level of satellite development.