Abstract: The research focuses on China’s ecological environment quality and financial and economic system. A four-sector endogenous growth model with variables of ecological environment and fiscal decentralization was constructed. The mechanism of economic activities such as fiscal decentralization, tax burden and R & D innovation on China’s ecological environment was comprehensively investigated. According to this, static and dynamic panel models and threshold models were further constructed, and empirical research was carried out on the heterogeneity of different regions. The conclusions are as follows.（1）Fiscal decentralization and tax burden have a deteriorating effect on environmental quality, while the synergy of the two produces a dilution effect that weakens each other; environmental quality itself has a lagged effect.（2）The western region shows a special trend that tax revenue improves the environment and a strong advantage of innovation and research. The central region shows a special promotion effect of human capital and GDP per capita environment. The eastern coastal areas show a special effect of increasing the proportion of FDI in the environment.（3）Fiscal decentralization and tax burden have non-linear effects on environmental quality, while GDP per capita and FDI share have double-threshold effect. Therefore, it is proposed to pay attention to the coordination and consistency of policy orientation. Cultivate the R & D innovation capability of enterprises, reduce unit energy consumption and improve the effectiveness of environmental protection expenditures;Based on the above conclusions, under the premise of fiscal policy coordination, the differentiated environmental promotion strategies for different regional geographical and economic heterogeneity characteristics are formulated to achieve a win-win situation for environmental protection and financial economy.