<p>The carrying capacity of the ecological environment reflects the interactive characteristics between the supporting role of the ecological environment and the social and economic pressure, and it is the key to maintaining the coordinated development of ecological environment quality and social and economic development. This study comprehensively calculates the spatio-temporal variation characteristics of ecological environment carrying capacity by constructing an evaluation system for ecological environment carrying capacity. The contribution characteristics of the nonlinear interaction of social, economic and ecological factors to the carrying capacity of the ecological environment were explored by using the gradient-enhanced decision tree model and Shapley additive explanation, and the corresponding optimization strategies were proposed. Research shows that: (1) The ecological and environmental carrying capacity of the Yangtze River Economic Belt decreased by 0.86% from 2000 to 2020; (2) From 2000 to 2020, the correlation between the ecological environment carrying capacity of the Yangtze River Economic Belt and ecological impact indicators decreased by 15.08%, while the correlation with social impact indicators and economic impact indicators increased by 1.29%. (3) From 2000 to 2020, the high-contribution indicators of ecological and environmental carrying capacity shifted from ecological factors to social factors. (4) The interaction among economic factors, social factors and ecological factors is greatly influenced by changes in social and economic factors. This research field provides scientific guidance for ecological environment security and sustainable social and economic development.</p>