Abstract: In order to meet the requirement of digital information system deployed in aircraft development, studying the aircraft structure product definition is very important. Based on anglicizing the method and process of aircraft development under the digital circumstance, the content and the form of aircraft structure product definition were summarized. The classes and the transformation principle of the axis and datum system were given for the digital aircraft design. The concept of the digital mockup and its usage were proposed, and the primary principle of the engineering drawings creation was discussed. The manufacture information and the quality control information were integrated into the digital definition to support engineering use. A way to manage all information integrated in the digital definition by layers and filters was introduced. The result consummates the concept of generalized digital definition and provides a reference instruction to implement digital system for aeronautical engineering.