Abstract: The collaborative detection and evaluation planning of ground and underground space is an important way to enhance the comprehensive carrying capacity of the city and promote the high–quality development of the city. In view of the new major scientific and technological problems such as "multi–plan integration" territorial spatial planning, coordinated and intensive utilization of ground and underground space aimed at the coordinated development of new urbanization and rural revitalization in China, taking Guanzhong plain urban agglomeration as the research area, based on the theories of the earth system science, the earth key belt, system, synergy and information, this paper puts forward the urban geological theory in the new period of urban–rural integration, coordinated detection, comprehensive evaluation and overall planning of ground and underground space; breaks through the key technologies of fine detection and modeling of underground space under the strong urban interference environment; proposes the risk prevention and control technology of ground and underground space based on groundwater; reveal the heat conduction law of geothermal fluid–exchanger in underground space, and raise the new green development technology of geothermal energy in underground space of "taking heat but not taking water". Which will provide the technique support for the urban planning, construction and operation management, land space planning, natural resource management, etc. And the theroies and the technologies have been successfully applied in many cities.