Abstract: To provide more convenient travel services for cardholders and meet the actual business demands of railway group companies, this paper designed a seat reservation system based on online transaction processing of China Railway Yintong Card. The system supported payment through the online account of Yintong Card, and retrieved seat resources in real time from the seat database to realize the seat reservation function. It adopted transaction consistency guarantee technology to ensure the reliable operation and data consistency of multi-business processes; it utilized message middleware to realize cross-system data interaction and improve the scalability and reliability of the distributed architecture; it applied real-time data synchronization technology to guarantee timely information updating and meet the data usage demands of front-end services. Practical application shows that the system effectively satisfies the travel demands of China Railway Yintong Card passengers for assigned seating and orderly boarding, and provides strong technical support for the popularization and application of Yintong Card in intercity railways.