Taking the corporate bonds issued by A-share listed companies on the Shanghai and Shenzhen Stock Exchanges from 2010 to 2021 as samples, this study empirically examines the impact of disclosing customer information on bond default risk. The results show that voluntary disclosure of customer information exacerbates the bond default risk, with a more significant effect observed in companies with high proprietary costs and high financing constraints. However, the issuance of green bonds by companies remains unaffected. Mechanism tests indicate that increased operational risk and lower institutional investor ownership are important pathways through which voluntary disclosure of customer information affects bond default risk. The research suggests that companies need to carefully consider the risks associated with disclosing customer information and formulate information disclosure strategies prudently.