As a core driving element of the new quality economy, government data has an important impact on macro national governance and micro enterprise operation. Combined with the practice of government data openness in recent years, this paper constructs a three party evolutionary game model of government, enterprises and accounting firms, to elucidate the impact effects and operational mechanisms of government data openness on audit quality, followed by empirical validation. The study confirms that, firstly, government data openness significantly promotes audit quality. Second, the “quality improvement” effect of information asymmetry improvement and the “efficiency enhancement” effect of enterprise digital transformation are the mediating mechanism. Third, the characteristics of surplus management, risk taking, property rights and internal control in the enterprise dimension, and the characteristics of government’s digital attention, marketization level and Internet penetration in the regional dimension all lead to differentiated effects. Further findings reveal that government data openness and improved audit quality synergistically alleviate financing constraints, thereby serving the high quality development of the real economy. The conclusions fully validate the economic benefits and social value of open government data, and have positive implications for the development of auditing standards.