Using the Green Factory Directory and supply chain matching data， it explored the influence of green factory identification on supply-chain green governance from the perspective of dual legitimacy. The results show that customers identified as green factories significantly enhance green innovation of upstream suppliers， and supply chain linkages amplify this effect. Mechanism analyses reveal that the impact is primarily achieved by activating suppliers’ motivations for compliance legitimacy and strategic legitimacy. Specifically， the promotion effect varies with the characteristics of green factory customers and the competitive landscape of suppliers， while compliance-oriented and strategy-oriented green innovation increase. Drawing on the strategy tripod framework， it further demonstrates that green factory customers， acting as market forces， effectively compensate for weak government environmental regulations at the macro level and the absence of executives’ environmental backgrounds at the micro level. Economic consequence tests confirm that suppliers’ green innovation leads to significant improvements in both environmental and financial performance. The conclusion provides a theoretical foundation for stimulating demand-driven green innovation and fostering policy coordination and strategic alignment among micro-level entities in the construction of the green system.