Abstract: By collecting the panel data of the Yangtze River Delta urban agglomeration over the ten years from 2013 to 2022, this article constructs an evaluation system for the level of ecological civilization construction in the Yangtze River Delta urban agglomeration based on four aspects: social development, environmental pollution, resource consumption, and environmental protection. The entropy weight TOPSIS method is adopted to measure the level of ecological civilization construction in the Yangtze River Delta urban agglomeration. Methods such as three-dimensional kernel density estimation, spatial autocorrelation, and spatial distribution maps are used to analyze the evolution characteristics of the spatio-temporal pattern of the ecological civilization construction level in the Yangtze River Delta urban agglomeration. The results show that: (1) From the perspective of measurement results, the overall level of ecological civilization construction in the Yangtze River Delta urban agglomeration shows an upward trend, but it still remains at a relatively low level. (2) In terms of the characteristics of temporal evolution, during the research period, the level of ecological civilization construction in the Yangtze River Delta urban agglomeration presents the evolutionary characteristic of continuous rise, but there are differentiating features among cities. (3) In terms of the characteristics of the spatial pattern, the level of ecological civilization construction in the Yangtze River Delta urban agglomeration is not randomly distributed but shows a significant positive spatial correlation. The local spatial pattern is mainly characterized by high-high and low-low agglomeration areas, and each has formed a contiguous spatial pattern. It is proposed that the concept of joint protection and governance of the ecological environment in the Yangtze River Delta urban agglomeration should be thoroughly implemented, the coordinated cooperation among the cities in the Yangtze River Delta urban agglomeration should be promoted, and the level of ecological civilization construction in the Yangtze River Delta urban agglomeration should be jointly improved.