A digital twin city refers to a virtual model that replicates the real city in real time through digital technologies and data simulation. It represents the application of the "digital twin" concept in urban planning and management. By constructing a full-element digital twin city, closely integrating intelligent infrastructure development, the extensive application of AI technologies, and a standardized smart city framework, it connects underlying terminal facilities and leverages data to drive upper-layer industry applications, providing technical empowerment for a digital twin–based smart city.