The aero-engine assembly is the terminal and crucial stage in its manufacturing process, characterized by intensive technology, funds and high-quality labor. Assembly simulation provides the important measures to improve manufacturing accuracy, production efficiency and quality level. However, the traditional geometric-level assembly simulation based on design model encountered limitations more and more. Associating the numerous on-site process decision requirement and the development prospective of intelligent assembly production line driven by big data, it is very important and urgent to develop both the physical modeling and simulation upon: from the micro-scale contact of assembled surface to the complex assembling deformation prediction, and the systematic modeling and simulation upon the big data correlation analysis between manufacture and engine performance. This paper makes preliminary analysis and prospect on key technology issues and development of aero-engine assembly simulation, and provides some suggestions.