By analyzing the industry progress of smart architecture at home and abroad, the paper integrates the design concept of digital twin, and constructs dynamic replicas of the whole life cycle of people, environment, architectural space, equipment and facilities in the cloud digital space. The digital intelligent building system platform with learning and evolution ability can realize through the organic integration of BIM three-dimensional digital base map based on building space, the three-dimensional perception Internet of things of facilities and equipment, the historical and real-time prediction of environmental dynamic data and people-oriented application services.