<p>Urban environmental legislation and justice contribute to the sustainable development of the region by providing environmental legal reference and hearing environmental cases. When interconnecting them, urban environmental legislation and justice mutually support and reinforece in environmental protection and a synergistic effect will ensure he effective implementation and fair adjudication of environmental laws. However, the detail effects and mechanisms through which synergy effect alters the corporate green transition remain a question. Utilizing panel data encompassing China’s A-share listed companies and prefecture-level cities from 2008 to 2022, we construct synergy effect and fixed effect regression model. Our research indicates that the synergy effect of urban environmental legislation and justice facilitates green transition of listed companies, with a regression coefficient of 0.13. Besides, we discover that the synergy effect exhibits heterogenetities in city, enterprise and law charateristics. In addition, we also finds that mechanisms are mainly through improving executives’ green perceptions and improving enterprises’ green management innovation. This study further also revealed a positive impact that the synergistic effect will affect the risk-taking of listed companies. This research has theoretical and practical significance for enhanceing the green transition of listed companies through urban environmental legislation and justice.</p>