In the new stage of China’s urban development from large-scale incremental expansion to stock improvement and efficiency improvement, underground space, as an important land space resource, has become increasingly prominent because of its strategic value and potential. Promoting the transformation of underground space development and utilization from engineering construction orientation to system governance and comprehensive utilization is an important apprach to implement the requirements of urban connotative development and improve the efficiency of resource and space utilization. The large-scale development of underground space development and utilization drives the agglomeration and systematic development of underground space related industries, which lays a realistic foundation for the formation of underground space economic form. From the professional perspective of the comprehensive utilization of underground space and the development of industrial system, this study explains the economic connotation of underground space. Underground space economy refers to a comprehensive economic form characterized by full chain coordination, full life cycle operation, and continuous value creation, which is gradually formed around the investigation and evaluation, planning and design, engineering construction, equipment manufacturing, operation and maintenance, service management, and other activities of underground space resources. On this basis, based on the analysis logic of industry, scenario, system, and economic result, this study combs the policy background and resource endowment of underground space development and utilization, and explains the connotation characteristics and formation logic of underground space economy from the perspective of underground space comprehensive utilization and industrial system development. The overall framework of the underground space industry system and the key direction of its evolution to the underground space economy are analyzed. Combined with urban renewal and national security needs, the main issues that restrict the economic development of underground space are identified. The study holds that the underground space economy is the inevitable result of the continuous improvement of the comprehensive utilization level of underground space and the agglomeration of related industrial activities, which is of great strategic significance to promote the high-quality development of cities and ensure the long-term security of the country.
YI et al. (Sun,) studied this question.