The article uses panel data of 30 provinces (autonomous regions and municipalities directly under the central government) in China from 2005 to 2018, and uses the three-system coupling model to measure the three-system coupling coordination degree of population age structure, consumption structure, and industrial structure. The calculation results show that the three-system coupling coordination degree of China’s population age structure-consumption structure-industrial structure is low, but the overall trend is increasing year by year. In order to further reveal the cause of the three-system coupling coordination, this paper examines the influence of the two-system coupling coordination of the population age structure, consumption structure, and industrial structure on the coupling coordination of the three systems. The spatial center of gravity model is used to analyze the degree of spatial matching between the two systems, and it is found that the increase in the degree of spatial matching between the twosystem of consumption structureindustrial structure gradually highlights the supporting role of the coupled coordination of consumption structure-industrial structure on the coupled coordination of the three-system. The decline in the efficiency of the spatial allocation of the two-system of population age structure-industrial structure has hindered the role in supporting the coupling and coordination of the three-system. This paper clarifies the causes of the formation of the coupled coordination of the three-system and provides countermeasures to improve its level of coupled coordination.