As the strategic equipment for a powerful country, aero-engines are considered as the integrations of precision processing and cutting-edge technologies. The development of aero-engine relies on the close cooperation of full lifecycles(i.e., de-sign, manufacturing, testing, maintenance), to meet the strict requirements like high-performance, high-reliability, and long service life, etc. Based on multi-source virtual assets(i.e., data, models, and services)and multi-type digital technologies(i.e., simulation, prediction, and optimization), aero-engine digital twin engineering promises to explore the full lifecycle-based innovative modes and interdisciplinary collaboration-based efficient platforms. In this case, the capacities of aero-engines throughout their entire lifecycles can be greatly improved, giving new impetus for the accelerated development of entire chain in aero-engine industry. In this study, 18 challenges of aero-engine digital twin engineering are presented firstly; in addition, by reviewing the digital twin researches in aero-engine full lifecycles, the shortcomings on theories, software, and standards are revealed; thirdly, based on the 5D model of digital twin, ‘eye model’ architecture of digital engineering and architecture of digital experiment, testing and validation proposed by the authors’ team, the connotation, systematic framework and key technologies of aero-engine digital twin engineering are proposed; finally, several suggestions are provided to advance aero-engine digital twin engineering. The current efforts aim to illuminate pathways for enhancing the support capabilities in full lifecycles, and enabling a leap in digital/intelligent development for aero-engines.