On a selection of the inter-municipal panel data of the Yangtze River Delta from 2010 to 2019, an analysis has been made of the impact of environmental regulation on high-quality economic development by using the spatial Durbin model and the mediation effect model. The research shows that current environmental regulations help to significantly promote the high-quality economic development, with an inverted U-shaped relationship between the two. Environmental regulations exert a significant positive spillover effect on the high-quality economic development, with the implementation of local environmental regulations promoting high-quality economic development in areas with close economic ties. Upgrading industry structure is an important path for environmental regulations to facilitate a high-quality economic development. Therefore, it is necessary to increase the implementation of environmental regulation, give full play to the positive effect of environmental regulations on the spatial spillover, and accelerate the optimization?and upgrading of the industrial?structure, thus enhancing the high-quality economic development level of the Yangtze River Delta.