In this paper, the PLS-SEM model is introduced to construct the intermediary effect model of urban-rural fringe in the interaction between urbanization and ecosystem health. Firstly, the urban-rural fringe was demarcated by the k-means clustering method, and the accuracy of k-means and clustering was evaluated using the silhouette coefficient (SC) and consistency ratio (CR). Then, the urban-rural fringe, urbanization, and ecosystem health data were collected, analyzed, and constructed. Finally, based on the PLS-SEM model, the mediating effect model of urban-rural fringe in the interaction between urbanization and ecosystem health was constructed and analyzed. The results show that: (1) The urban-rural fringe is more accurate: the urban core (UC) and near-urban core (NUC) areas are basically consistent with the current urban core areas, CR values are more than 77%. (2) The mediating effect of the urban-rural fringe in the interaction between urbanization and ecosystem health was significant (-0.204/-0.214), the hypothesis is true. (3) Suppose that there are two mediating effect paths: a. Population urbanization through economic urbanization and spatial urbanization, taking the urbanrural fringe as an intermediary has an impact on ecosystem health (PU-EU-SU-UR-EH). b. Population urbanization through economic urbanization, taking the urban-rural fringe as an intermediary has an impact on ecosystem health (PU-EU-UR-EH).