<p>Identifying and addressing strategic behavior in corporate ESG disclosures is essential for promoting green, low-carbon development and supporting China’s modernization. This study employs the Ambient Air Quality Standards—an initiative designed to enhance environmental information transparency—to examine the impact of environmental information openness on ESG disclosure strategic behavior. Based on a multi-period DID approach, the findings indicate that environmental information openness effectively reduces firms’ strategic behavior in ESG disclosure. External governmental oversight and internal corporate improvements function as mediating mechanisms operating through multiple channels. Further analysis of moderating effects shows that the inhibitory influence is more pronounced when governmental intervention is stronger and public environmental awareness is higher. Moreover, heterogeneity analysis indicates that this effect differs across ownership structures, corporate life-cycle stages, and market institutional environments. This study quantitatively assesses the strategic influence of environmental information openness on corporate ESG disclosure and offers critical insights for policymakers seeking to improve ESG disclosure frameworks and promote high-quality ESG development.</p>