Abstract: The railway 12306 Internet Ticketing and Reservation System（referred to as 12306）has complex levels and numerous functions, and its operation and maintenance diagnosis needs a lot of personnel and time. In view of this situation, the paper introduced knowledge graph technology to model 12306's operation and maintenance knowledge, gave the construction process of 12306's operation and maintenance knowledge mapping, and designed 12306's intelligent operation and maintenance architecture, described the key technologies such as root cause determination, anomaly detection, and intelligent decision-making, implemented the automation and intelligence of 12306 operation and maintenance, saved the labor cost and time cost of diagnosing and handling problems, improved the operation and maintenance efficiency, and provided technical support for 12306 operation and maintenance.