This study investigates the effects of social dishonesty on the maturity mismatch of investment and financing in Chinese companies. Our findings reveal that social dishonesty significantly exacerbates the maturity mismatch, with the issue being particularly pronounced in non-state-owned enterprises, high-tech industries, and developed financial markets. Nevertheless, enhancing the quality of corporate accounting information disclosure, improving stock liquidity, achieving good ESG performance, and undergoing digital transformation can reverse the role of social dishonesty in exacerbating the maturity mismatch of investment and financing. This research highlights the significant influence of social dishonesty on corporate financial strategies within the framework of informal institutions.