Based on an empirical model, this paper examines the impact mechanism of digital transformation on corporate financing constraints, with a focus on testing the mediating role of internal control. The results show that digital transformation can significantly alleviate corporate financing constraints, where internal control plays a critical mediating and bridging role. Specifically, digital transformation indirectly eases corporate financing pressure by improving the quality of internal control. Further heterogeneity analysis reveals that the above alleviation effect is more pronounced in non-state-owned enterprises and enterprises in the eastern region of China. In contrast, no significant short-term effect is observed in high-tech enterprises, due to the high investment and uncertainty associated with their transformation process. Based on the findings, the government should further improve the policy environment to promote the coordinated development of corporate digital transformation and internal control. Enterprises also need to strengthen the construction of internal control to fully capture the financing convenience brought by digital transformation.