The construction of subcenters is considered an effective measure to solve the diseases in big cities and improve urban competitiveness. China takes the planning and construction of the Beijing urban subcenter as a major national decision-making deployment. Therefore, the establishment of a scientific and reliable evaluation index system for the urban subcenter is of great significance to the public sector to diagnose urban problems and improve urban performance management. Under the guidance of system theory, this paper establishes the governance evaluation index system of the Beijing subcenter based on the five subsystems: economic subsystem, social subsystem, cultural subsystem, ecological subsystem, and administrative subsystem, and 29 secondary indicators. After comprehensively examining the panel data of the overall Beijing urban system during the construction of the subcenter (2010–2019), the entropy method is used to objectively assign the value of the Beijing urban subcenter (Tongzhou District), and it is compared with other 15 municipal districts. The derivation of the development dynamic evolution of the Beijing urban subcenter is completed through the geospatial visualization and the linear regression fitting. It is found that the comprehensive index of urban subcenter governance in Beijing shows an upward trend year by year and has developed by leaps and bounds under the promotion of the central policy. Driven by Beijing’s subcenter strategy, the development model of the whole of Beijing has moved from a typical center diffusion model to a dual center to a subcenter and even a diversified development pattern. This paper proposes to lead urban development with the concept of high-quality development, adhere to innovation-driven, improve urban comprehensive carrying capacity through urban software and hardware construction, and realize regional coordinated development on a larger spatial scale.