Green finance is closely linked to economic development. At the same time, the reduction in carbon dioxide emissions is a necessary part of economic development. Based on a composite index of green financial development, this study uses panel data for 276 cities in China from 2011 to 2020 and a general equilibrium model based on endogenous growth theory to explore the impact of green finance, decarbonization on high-quality economic development. In addition, the paper examines again the links between the three from the perspective of knowledge networks. The study found that Green finance has the potential to greatly support high-quality economic development, and the combination of green finance with decarbonization has an even greater impact. The air circulation index is used as a tool variable to address the endogenous problem in this research, which investigates the intrinsic logic of these two effects. The preceding conclusion is valid. This paper focuses on the existing ways of interacting. The findings indicate that changes in industry structure and R&D expenditure will have a more significant impact. At the same time, from the standpoint of knowledge networks, this research demonstrates an inverted U-shaped link between knowledge network centrality and structural hole and high-quality economic development. The interaction demonstrates that knowledge networks' centrality and structural hole play a beneficial regulatory function in green financing, decarbonization, and high-quality economic development. This article also examines the heterogeneity between the two. We also find that this impact is more significant in the eastern region, the central region, the Yangtze River Economic Belt, and the Beijing–Tianjin–Hebei region. The results of the empirical study have important implications for green finance planning and decarbonization in China. Improve the green financial development system, coordinate the regional economy’s high-quality development level, and serve as a knowledge network.