The invention provides a smart city platform for urban governance, which includes establishing a city CIM early warning model, a Urban three-dimensional transportation thematic system, a urban environmental information thematic system, a urban government affairs service thematic system, a urban economic operation thematic system, a urban safety production thematic system, a urban infrastructure thematic system based on 3D GIS model and AI intelligent early warning , to achieve the monitoring, processing and operation of the overall intelligence of the city. Through the integration ability of urban thematic application to information and urban Internet of Things perceptual resources, it plays a universal role in the three-dimensional transportation, economic operation, safety in production,infrastructure, government services and other important livelihood services. The application in urban governance and public services is conducive to promoting the coverage of basic public services indifferent levels, different regions and different groups, effectively improving the level of public services and their equal coverage, assisting government decision-making, crisis management, and enhancing government governance capacity.