The DMU（Digital Mockup）is a digital representation of aircraft products，which is a product model consisting of all 3D digital information related to the aircraft. It can be used for engineering design, engineering analysis (space analysis, movement analysis, assembly and disassembly simulation, manufacturing and maintenance inspection), engineering simulation, etc. The DMU radically reformed the traditional aircraft collaborative development, creating a new phase of aircraft collaborative development. With the development of digital technology and computer network technology, the role and status of DMU in collaborative development of the aircraft digitalization is developing constantly. In this paper, the development process of the DMU is summarized according to the history of the aircraft digital cooperation.