In the digital economy era，data has become a new resource for urban development and data intelligence a new technology in urban sustainable development. How to exploit the value of urban data is an important topic for the development of new smart cities. New smart city means a system that integrates both digital infrastructure and traditional infrastructure，and urban brain is the digital infrastructure that supports urban sustainable development. Just like a data intelligence operating system，its key is to optimize urban public resources by using the full real-time urban data resources in a complete way. In terms of internet+ government services，refined urban governance，public security，transport and other fields，urban digital infrastructure has created data value for cities.