<p>Rapid economic growth has been accompanied by a steady increase in greenhouse gas emissions, triggering frequent extreme weather events and global ecological degradation. As key entities in policy implementation, enterprises face a critical question: how to drive green innovation in the digital era—a task vital to economic green transformation and environmental protection. To address this, this study focuses on A-share Listed companies from 2012 to 2020, employing the triple difference method and stepwise regression to examine the impact of synergies between voluntary environmental regulation, represented by green factory certification, and digital transformation on corporate green innovation. The findings show that such synergies significantly boost green innovation, and this conclusion is validated through a series of robustness tests. Mediation analysis further reveals that the synergies drive corporate green innovation through two channels: alleviating external financing constraints and optimizing internal governance structures. Additionally, heterogeneity analysis indicates that the promotional effect is more pronounced in regions with stricter environmental regulations and more advanced industrial structures. A deeper investigation finds that the degree of market monopoly exerts a negative moderating effect on the relationship between these synergies and corporate green innovation. By assessing the effectiveness of voluntary environmental regulation in the digital context, this study provides policymakers with a scientific basis for refining policy design and implementation strategies. It also offers novel theoretical perspectives to advance corporate green innovation, contributing fresh insights to the intersection of environmental regulation, digitalization, and sustainable development.</p>