Abstract: In the context that air,as a public resource,is difficult to exclude and lacks clearly defined property rights,free-riding behavior becomes prevalent during the governance process. This makes air pollution a typical externality issue,leading to market failure. The government,as a key supplier of environmental public goods,has a well-established theoretical foundation for its intervention in pollution control. However,in real-world governance,the motivation and capability of government to manage pollution can be influenced by multiple factors,such as the spillover effects of environmental governance outcomes and the inherent tension between environmental constraints and administrative performance evaluations. Furthermore,the local government-led governance model often faces problems of weak enforcement and a lack of public trust. With the shift in policy approach,environmental governance is gradually evolving from a single government-led model to a multi-actor co-governance structure involving government,enterprises,and the public. Government information disclosure is increasingly regarded as a crucial institutional instrument for breaking down information barriers,activating social supervision,and enhancing governance performance. Building a co-governance framework based on information transparency has become a key direction in current policy development. This transition reflects the growing demand for institutional mechanisms that promote accountability,responsiveness,and participatory governance in tackling environmental issues. Based on the above background,this paper investigates whether and how government information disclosure can promote improvements in pollution governance performance. The study systematically analyzes the Government Work Reports of 282 prefecture-level cities in China from 2012 to 2022. Using the Word2Vec model,semantically similar terms are identified,and word frequency is calculated to develop a city-level government information disclosure index that is both dynamic and comprehensive in scope. This index captures the evolving emphasis of local governments on information disclosure over the years. In terms of empirical methodology,we adopt a panel fixed-effects model to identify the impact of government information disclosure on the effectiveness of air pollution governance,with the annual average PM2.5 concentration serving as a proxy variable for pollution intensity. City and year fixed effects are included to control for unobservable heterogeneity across time and space. In addition,mediation analysis is employed to explore the pathways through which information disclosure affects air quality,and heterogeneity analysis is conducted under different city characteristics to identify the boundary conditions of institutional effectiveness. This multi-dimensional empirical design enables a more nuanced understanding of both the direct and indirect effects of institutional transparency on environmental outcomes. Empirical results show that improvements in government information disclosure are significantly associated with reductions in city-level PM2.5 concentrations,indicating that government information transparency plays a positive role in promoting more effective pollution governance. Furthermore,the effects exhibit significant spatial spillovers,suggesting that information disclosure not only improves local environmental performance but also strengthens governance incentives in neighboring cities through mechanisms such as competition or imitation. Regarding the mechanisms,information disclosure enhances the observability and enforceability of environmental regulations,thereby increasing policy deterrence. At the same time,transparency reduces uncertainty and raises the expected cost of pollution,encouraging firms to increase investment in green innovation to reduce emissions. These mechanisms demonstrate that transparency is not merely symbolic but materially alters the cost-benefit calculus for local governments and enterprises alike. In addition,the study finds a substitution effect between government information disclosure and public participation. In other words,as the supply of information becomes more sufficient,the effect for the public to spontaneously engage in environmental governance diminishes. Heterogeneity analysis reveals that the policy demonstrates stronger effects in non-resource-based cities,cities with lower political-business integrity,cities with stronger digital infrastructure,and cities with less frequent government turnover. This suggests that information disclosure systems can serve a compensatory governance function,especially in areas with better technological foundations or weaker institutional environments. The effectiveness of such disclosure,therefore,hinges not only on the volume of information but also on the local socio-political and digital context. Based on the above findings,this study proposes five policy recommendations. First,improve the institutional framework for government information disclosure by enhancing the quality and coverage of released information to support cross-regional coordination. Second,strengthen the institutional incentive effects of information transparency,encouraging local governments to intensify environmental regulation and increase enforcement transparency. Third,enhance policy clarity and stability to reduce firms' uncertainty and promote green innovation,forming a positive feedback loop driven by transparency. Fourth,foster complementary interaction between government disclosure and public participation by tailoring mechanisms to local strengths and weaknesses,thereby amplifying governance synergy. Fifth,implement context-specific information disclosure strategies that address regional disparities,such as infrastructure constraints or weak institutional foundations,to reinforce governance capacity in less-developed areas. Together,these strategies aim not only to reduce pollution but also to reinforce institutional trust,policy responsiveness,and public accountability in environmental governance. Collectively,these recommendations aim to systematically activate the governance potential of information disclosure,facilitate a multi-actor co-governance structure led by governments,supported by enterprises,and coordinated with public engagement,thereby contributing to improved air quality and the broader goal of green transformation