Abstract: Objective In the GBA（Guangdong-Hong Kong-Macao Greater Bay Area）, regional rail transit systems form independent networks, characterized by several ticket issuers, diverse standard systems, various ticket types, numerous fare policies, and multiple clearing entities. In the context of cross-regional and cross-system integration, the rail transit line network in GBA aims for interoperability. For the convenience of passengers completing their entire journey with a single-ticket and one-time entry/exit, it is essential to enable cross-regional fare calculation, accurate revenue clearing, and unified ticket access. In response, it is necessary to investigate the interoperation application design of ticket clearing system within the area. Method By analyzing fare policies and pricing methods in the GBA, rules for GBA ticketing and key interoperability are designed. Through comparative analysis of clearing technologies, a recommended technical approach for interoperation and clearing within GBA is proposed. Based on post-integration requirements—fare calculation, ticket interoperability, transaction clearing, data sharing, parameter management, and passenger service across regions—a centralized GBA clearing center and its functions are designed A subsystem for marking clearing path channels is deployed at key inter-regional interchange stations such as intercity railway-to-metro and metro-to-metro, using tickets as a carrier to track passenger travel routes for accurate fare calculation and revenue clearing. Furthermore, by analyzing the current state of ticketing interoperability across GBA cities, technical design for ticket interoperability is optimized. Result ＆ Conclusion A solution is proposed for achieving one ticket access unified fare calculation and precise ticketing revenue clearing in GBA rail transit system.