<p>Climate change mitigation through the green transition of high-polluting enterprises presents a critical sustainable development challenge in emerging economies. This study examines the effectiveness of green credit policy in promoting environmental responsibility among China’s high-polluting enterprises, with particular focus on market-based mechanisms and transition pathways. Using a comprehensive environmental responsibility index, we employ a difference-in-differences model with dynamic marginal effect analysis to evaluate policy impact. The methodological framework incorporates time-varying interaction terms and mediation analysis to investigate implementation lags and transmission mechanisms. Our analysis reveals three distinctive contributions: first, green credit policy enhances environmental responsibility through market-based mechanisms rather than traditional regulatory approaches, though with a time-lagged positive effect on environmental responsibility, and effectiveness varying across ownership structures; second, the policy operates through a novel dual-pathway framework, which are financing constraints and green technology innovation incentives, with financing constraints exhibiting superior effectiveness; third, ownership-based heterogeneity significantly moderates policy impact, with non-state-owned enterprises showing stronger environmental responsibility improvements despite facing greater financing constraints, while state-owned enterprises receive preferential credit access. These findings show the complex interplay between financial policy and corporate environmental behavior, and provide practical guidance for policymakers and financial institutions in optimizing transition finance approaches for high-polluting enterprises.</p>