Abstract: In the context of four-network integration, it is of great significance to rail transit fare integrated development for the connection of intercity railway and metro fare systems, and to realize billing zone seamless interchange. By comparing practical experiences of domestic and abroad billing area interchange fare systems, based on the development of Guangdong-Hong Kong-Macao Greater Bay Area Intercity Railway and metro line network fare price, the interchange mode, the fare system of intercity railway and metro in the trend of integrated development are analyzed. The adaptability of strategies such as the valuation of intercity railway and metro, the valuation of cross-system and cross-section under metered fare system are analyzed. Results show that the billing area interchange mode and the same-system cross-section adopting the pricing strategy of ′non-segmentation, no re-starting′ and the cross-system adopting′segmentation, re-starting′ is more in line with the Guangdong-Hong Kong-Macao Greater Bay Area rail transit fare integration development.