Abstract: Urban rail transit is a critical component of modern urban transportation systems, and its safe and stable operation plays a vital role in enhancing transportation efficiency and improving residents’ quality of life.Traditional operation and maintenance largely rely on manual expertise, making it challenging to achieve comprehensive monitoring and accurate assessment of equipment status, which is increasingly insufficient to meet the growing complexity of rail transit maintenance demands.Intelligent operation and maintenance effectively address these limitations by leveraging advanced technologies.Starting with the structure of the intelligent operation and maintenance system, the functions of each subsystem are analyzed in detail based on their respective domains.The key maintenance technologies and engineering practices of intelligent operation and maintenance are explored from two key aspects: smart network infrastructure and specific application technologies.Finally, the current research status of intelligent operation and maintenance is summarized from the perspectives of system structure, operation and maintenance models, and industrial development, followed by a discussion of its future development directions.