With A-share listed companies in Shanghai and Shenzhen from 2007 to 2022 as research samples,a fixed effects model is used to empirically test the governance effect and mechanism of supply chain discourse power on debt maturity mismatching. The study finds that suppliers and customers with discourse power can ex-ert governance effects on debt maturity mismatch. Mechanism tests indicate that suppliers and customers with discourse power will make exclusive investments with enterprises,suppressing enterprises' irrational investment behavior. Enterprises,out of precautionary motives,increase cash holdings to protect themselves against external environmental uncertainties and market risks,thereby alleviating debt maturity mismatching. Furthermore,im-proved innovation performance and intense industry competition can enhance the governance effect of suppliers/customers with discourse power on debt maturity mismatching. This governance effect is more pronounced in non-state-owned enterprises and enterprises with high internal control quality.