Abstract: Objective: With the trend of digital transformation in urban rail transit, the most urban rail transit operation units in China are committed to the construction of a smart operation and maintenance system for urban rail transit. In\|depth research is needed on the problems and pain points that encountered in the application process of smart operation and maintenance to urban rail transit. Method: The application of smart operation and maintenance in Shanghai urban rail transit is presented, proposing the use of digital twins in the smart operation and maintenance platform for urban rail transit. Solutions for processing massive and heterogeneous data, establishing smart management business processes for effective maintenance and repair, and integrating information resources are proposed. Based on these solutions, the functional architecture of smart station platform and smart maintenance platform is developed, and a cloud computing platform for real\|time data and business integration between the urban rail transit network and stations is described. Result &Conclusion: Intelligent operation and maintenance require uniform planning from the beginning of construction. Based on digital twinning, intelligent operation and maintenance applications for urban rail transit can improve the level of intelligent perception of equipment, reduce the intensity of manual operation and maintenance, while improving the quality and reducing the cost of operation and maintenance.