To promote “four-network integration” of rail transit and better support the development of urban agglomerations and metropolitan areas, this study deeply analyzes the connotation and characteristics of the “four-network integration” and summarizes its role and significance. On this basis, the study systematically reviews the four-network integration planning practice of Guangzhou's rail transit and proposes recommendations from the aspects of top-level design, operational organization, and institutional mechanisms. The research results indicate that to achieve high-quality four-network integration, it is essential to firstly establish a rail functional hierarchy system suitable for metropolitan area development based on its spatial scale, central system, and passenger flow demand. Secondly, for a certain direction of passenger flow corridor, it is necessary to fully consider the characteristics of passenger flow demand, and study the reasonable configuration of different lines within the same channel from the perspective of leveraging the advantages of various levels of track functions. Thirdly, the appropriate network integration method should be selected from a holistic perspective, balancing demand and cost while considering the applicability of interconnectivity and hub node transfers. Finally, efforts should be made to promote mutual trust in security checks and interoperability of ticket systems to facilitate passenger travel.