The issues of supply chain information disclosure and performance manipulation concern the safe operation of Chinas supply chain and the business development of corporations. Taking listed corporations on the Shanghai Stock Exchange from 2015 to 2022 as the research sample, this study explores how supply chain transparency under associative relationships affects performance manipulation. The research shows that the enhancement of supply chain transparency under associative relationships can curb performance manipulation. Mechanism tests reveal that supply chain transparency under associative relationships suppresses performance manipulation by enhancing customer stability, reducing information asymmetry, and lowering external transaction costs. Further research indicates that the governance effect of supply chain transparency on performance manipulation is more significant when a company has low supply chain dependence, high information disclosure, a weak market competition environment, or a poor external supervision environment. Compared with customer transparency, supplier transparency under associative relationships has a more significant inhibitory effect on performance manipulation; compared with negative performance manipulation, supply chain transparency under associative relationships has a more significant inhibitory effect on positive performance manipulation. The research conclusions provide some inspiration for corporations and regulatory authorities to further improve the information disclosure system and maintain a fair and transparent order in the capital market.