Abstract: The authors systematically review the application status and research trends of digital twin technology in the operation and maintenance phase of urban underground spaces. First, using bibliometric methods, 847 academic publications published between January 1, 2019 and April 21, 2024 are analyzed to identify and summarize the core technologies and application strategies of digital twins in this domain. In addition, key functions, including real-time data monitoring, continuous model updates, simulation, and prediction, are comprehensively summarized from a technical perspective. Furthermore, four primary application areas of digital twin technology in urban underground spaces are discussed: structural health monitoring and management, facility monitoring and management, energy and environmental management, and disaster response and emergency management. Finally, based on current technological developments and practical needs, it is suggested that future research should prioritize building a systematic index system and advancing multi-modal intelligent sensing technologies to enhance the safety, reliability, and efficiency of urban underground spaces. In addition, achieving more efficient and precise operation and maintenance management will require the development of models that account for the evolution of operational behavior under the influence of multiple interacting factors, as well as research into multidimensional intelligent evaluation technologies.

Key words: digital twin, urban underground space, operation and maintenance management, structure monitoring, facility supervision, energy environment, disaster emergency