<p>Corporate ESG greenwashing refers to the dissemination of false or misleading ESG disclosures. This research investigates whether green finance reform can mitigate ESG greenwashing and explores the underlying mechanisms, employing a double machine learning framework. The baseline model utilizes a random forest algorithm, revealing that green finance reform significantly curbs ESG greenwashing at the 1% significance level (coefficient: −0.043). Robustness checks—including alternative dependent variable, machine learning algorithms, sample splits, placebo test, and instrumental variable analysis—confirm the result’s validity. Mechanistically, the reforms inhibit greenwashing through four channels: (1) intensifying stakeholder monitoring, (2) mitigating information asymmetry, (3) strengthening regulatory oversight, and (4) improving corporate environmental management systems. Policy implications highlight the need for governments to refine ESG disclosure frameworks and incentivize stronger internal governance within firms. The findings underscore green finance reform as a critical tool to align corporate sustainability claims with genuine practices. For regulators, establishing clear legal penalties for ESG misrepresentation and implementing mandatory, standardized disclosure requirements should become priorities.</p> Graphical abstract <p></p>