Based on the Brilliant digital twin operating system, a digital twin city is reconstructed in the digital space to match the physical city, promoting the digitization and virtualization of all elements of the city, real-time and visualization of the entire state, collaborative and intelligent management of urban operations, and achieving collaborative interaction and parallel operation between physical and digital cities. Through the construction and full sharing of digital twin cities, third-party vendors are supported to build various applications on the digital twin platform, achieving data-driven decision-making and fully integrating virtual and real aspects. This enables the operation, management, and services of cities to move from reality to virtuality, and can be modeled, simulated, evolved, and controlled in virtual spaces. At the same time, from virtuality to reality, it changes and promotes the optimal allocation of urban resource elements in physical spaces, opening up new models for the construction and governance of smart cities.