Digital transformation is a necessary path for the high-quality development of enterprises. Open government data helps break down data barriers, but can it drive digital transformation of enterprises? A quasi-natural experiment was designed using the Government Data Open Platform as an exogenous impact. Relying on the data of Chinese A-share listed firms between 2007 and 2022, a staggered DID model was used to empirically explore the impact and mechanism of government data openness on digital transformation of enterprises. The research showed that open government data has a positive effect on promoting digital transformation of enterprises, which can be indirectly achieved through cost savings and innovation driven effects. Further analysis revealed that the digital driving effect of government open data is more significant in low financing constraint enterprises, non-state-owned enterprises, and enterprises located in ordinary cities; and the establishment of the Big Data Administration Bureau, the construction of the Data Trading Platform, and the establishment of the provincial-level Government Data Open Platform have played a synergistic role in the digital transformation driven by government data openness. The research has expanded the relevant literature on the causes of enterprise digital transformation and the effects of government data openness policies, and it will provide empirical evidence for further promoting data openness and sharing, and building a digital government.