The invention belongs to the technical field of data fusion and sharing, and discloses a smart city data sharing system and method based on the XBRL standard, which associates, fuses, processes and analyzes the urban data into information, and fully shares the standard data resources, so as to provide the smart city with cross-domain, standardized, safe and reliable sustainable high-quality data.The intelligent city data sharing system based on XBRL standard comprises a standard specification module, a classification standard module, a component management module, a data link module, a storage library module, a data aggregation management module, a data retrieval module and a sharing exchange module. The system is located in the data and service support layer of the reference model of smart city construction, provide data and service integration for smart city, ensure the upper level for data convergence related requirements, provide various data services and shared resources required by the application, that is, through XBRL standards will be urban data association, fusion, processing, analysis into information after fully sharing standard data resources.