This study employs the data of Chinese A–share listed companies from 2007 to 2022, considers the implementation of the regional financial reform pilot zone policy as a quasi-natural experiment, and tests the impact of this reform on the financial asset holdings of nonfinancial firms by using a difference-in-difference model. Based on the findings, the regional financial reform restrains the financialization of nonfinancial firms through two paths: 1) promoting profit equalization, which reduces the return gap between real and financial investments; and 2) balancing the allocation of credit resources, which curbs corporate participation in shadow banking. Further analysis showed that the governance effect of the regional financial reform is especially prominent for firms in regions with lower administrative, market development, and financial development levels, especially in the central and western regions. In the economic consequences test, we found that the dampening effect of the regional financial reform on corporate financialization can promote real investments, especially innovation investments. These findings not only enrich the research on the determinants of corporate financialization and the economic consequences of the regional financial reform, but they also provide insights for financial reforms in other emerging economies.