Abstract: Coordinated development of the eco-environmental and socio-economic sectors has become a fundamental objective for the regional economic development of China. During this study, an evaluation index system was built by adopting multiple weight evaluation method, weighting method based on game theory and coupling coordination model to analyze the coupling coordinated relationship and affecting factors of eco-environment and socio-economy in 27 central urban agglomerations of the Yangtze River Delta Region in 2015 and 2020. The results show that forest coverage and higher education carry the highest weight in the indicator systems of eco-environmental and socio-economic development, respectively. Compared with 2015, the regional ecological environment quality and socio-economic development levels have improved significantly in 2020, and 77.78% and 88.90% of the cities showed upward trend in eco-environmental and socio-economic development, respectively. In terms of spatial distribution, the regional eco-environment and socio-economic development showed significant spatial autocorrelation and strong agglomerative effects, however, the spatial agglomeration of socio-economic development showed a slight downward trend. The number of cities with well-coordinated environmental and economic development increased from the central region to the central and southern regions, and the coordinated development of environmental and economic coupling in Zhejiang improved significantly. There were no cities in the central urban agglomeration with significant maladjustment, but there were still relatively few cities with extremely coupled and coordinated development. Structural equation model analysis shows that forest coverage, atmospheric environment, and economic structure have particularly significant effects on the coupled and coordinated development of regional environments and economies. Therefore, strengthening the implementation of specific measures, such as improving regional forest coverage, controlling air pollution and increasing land area income, will help jointly promote high-quality economic development and high-level ecological environment protection.