Through over 70 years of development, the World Meteorological Organization (WMO) has established a global data-sharing network that covers 193 members. This study analyzed the WMO’s meteorological data-sharing system from two aspects: system architecture and composition, and management norms and standards. The meteorological data-sharing system comprises the global observing system (GOS), the global telecommunication system (GTS), the WMO information system (WIS), and the global data-processing and forecasting system (GDPFS). Specifically, the GOS coordinates and schedules observational facilities from land and marine stations, aircraft, environmental satellites, and other platforms. The GTS manages the real-time collection and distribution of meteorological information. The WIS is responsible for discovering, accessing, and managing data and products. The GDPFS provides various climate forecasting data to users. By formulating a unified data policy and establishing this meteorological data-sharing system, the WMO has enabled the global sharing of Earth system science data in multiple fields, such as weather, climate, hydrology, atmospheric composition, cryosphere, and oceans. This study summarizes the achievements of WMO’s meteorological data-sharing system and its alignment with China’s relevant data strategy requirements. It assists in enhancing the understanding of international meteorological data-sharing activities and facilitating the construction of a similar multi-departmental comprehensive Earth observation data-sharing system in China.