Abstract: The "four-network integration" is a necessary initiative to build a metropolitan area on the rail, strengthen the benefits of rail transportation network, realize the sharing of resources, improve the efficiency of passenger travel and improve service quality. At present, there are many problems in rail transit network integration, such as institutional constraints, multiple planning and coordination, clear division of interests and rights, standard system compatibility and data management. Among them, data governance is the key issue of "four-network integration". This paper studied the key technologies of data governance of rail transit "four-network integration", including distributed storage, cross domain multi-party identity authentication, multi granularity and multi-dimensional encryption memory access, blockchain based traceability and other technologies. This research is of great significance for promoting the high-quality development of urban agglomeration and metropolitan area, and improving the quality and efficiency of rail transit.