Taking China's A-share listed companies from 2010 to 2022 as research samples, corporate cash flow is selected as the intermediary variable based on the perspective of debt tax shield, and the impact of corporate debt ratio on the financialization of real enterprises is tested. The empirical results show that there is a significant negative correlation between corporate debt ratio and the financialization of real enterprises.Corporate cash flow plays a partial intermediary role in the influence of corporate debt ratio on the financialization of real enterprises. There is a threshold effect of corporate debt ratio on the financialization of real enterprises. When the corporate debt ratio exceeds the threshold value, the inhibitory effect of corporate debt ratio on the financialization of real enterprises is significantly weakened. Agency problems will weaken the restraining effect of corporate debt ratio on the financialization of real enterprises. Compared with private enterprises, the negative impact of corporate debt ratio on the financialization of real enterprises is more obvious in state-owned enterprises.