Common institutional investors integrate a powerful information resource network by simultaneously linking multiple listed companies in the industry, affecting the investment structure and debt maturity arrangement of enterprises. This paper takes China’s A-share listed companies from 2007 to 2022 as the research sample, mainly exploring the relationship between common institutional investors and investment-financing maturity mismatch. The study finds that common institutional investors can help to improve investment-financing maturity mismatch. That is, the presence of common institutional investors, their shareholding ratio, and horizontal linkage all contribute to reducing the degree of investment-financing maturity mismatch. Mechanism testing shows that common institutional investors can effectively alleviate investment-financing maturity mismatch by driving enterprises to actively carry out high-quality supply-chain relationship governance, which includes enhancing the discourse power in the supply chain, improving the level of business credit, and reducing transaction costs in the supply chain. This creates more economic capacity in the production and operation process, and thus plays a positive role in actively improving investment-financing maturity mismatch. Expansion analysis shows that common institutional investors can collaborate with internal and external corporate governance mechanisms, with a more significant impact on enterprises with effective internal controls and higher media attention; common institutional investors can also compensate for the shortcomings of incomplete contracts and formal systems, and play a substitute governance role especially for vulnerable groups with poorer contract environments and weaker market competition. Economic effect testing finds that common institutional investors can further strengthen the stability of the supply chain system and promote sustainable development. From the perspective of supply-chain relationship governance, this paper provides certain insights to guide and support diversified shareholding by common institutional investors, optimize micro-enterprise resource allocation, prevent and resolve liquidity risks, and assist in the high-quality development of China’s real economy.