We study how public credit information affects corporate debt financing. Using the staggered rollout of China's Social Credit System as a quasi-natural experiment, we find that public disclosure of credit information significantly lowers corporate bond yield spreads. The effect is stronger in regions with stricter disclosure requirements and enforcement, and among firms with greater information asymmetry and weaker monitoring. Consistent with reduced informational frictions, the reform is associated with fewer bond covenants, lower secondary-market yields, and improved liquidity. Our findings highlight the role of digital public information in enhancing debt market efficiency.