This paper uses data from Chinese listed companies, urban development, and financial eco-environment index from 2005 to 2015 to empirically analyze the impact of financial eco-environment on corporate leverage and its dynamic adjustment. The results show that the financial ecological index and corporate leverage have a significantly positive relationship. That is, the deterioration of the financial ecological environment will cause the company’s leverage to decline. This effect is more significant in the samples of after 2008, in enterprises in the central and eastern regions, and in those with long-term liabilities. Furthermore, strengthening government intervention and the financing constraints faced by enterprises are found to be two important mechanisms driving the continuous decline in the leverage of enterprises due to the deterioration of the financial ecological environment. Finally, the impact of the financial ecological environment on the dynamic adjustment of leverage is examined. The results show that the deterioration of the financial ecological environment will reduce the speed of leverage adjustment. The conclusions of this paper have direct policy implications: when implementing relevant policies such as “de-leveraging” and supply-side structural reforms, special consideration should be given to the potential impact of the external financial environment. It is also necessary to encourage local governments to create a favorable financial ecological environment, provide necessary institutional guarantees for enterprises’ financing decisions, and further enhance the ability of financial services to support the real economy.