Using a sample of A-share listed companies from 2007 to 2022, this study employs the BERT large language model to construct an index of corporate policy-related information disclosure and examines its impact on the cost of debt financing. The findings indicate that corporate policy-related information disclosure significantly reduces the cost of debt financing, and this conclusion holds even after a series of robustness tests and discussions on endogeneity. Mechanism tests reveal that the information supplementation mechanism which based on disclosure content and the strategic orientation mechanism which based on disclosure behavior are the key channels through which corporate policy-related information disclosure reduces debt financing costs. Further heterogeneity analysis indicates that the cost-reducing effect of corporate policy-related information disclosure is more pronounced among private enterprises, firms with a more positive tone in their annual reports, and firms with a long-term debt structure.