In the context of a booming digital economy, data factor has emerged as a new factor of production driving enterprise transformation. Meanwhile, enterprises exhibit pronounced peer behavior in their application of data resources. How this peer effect affects corporate green technology diffusion represents a research topic worthy of in-depth exploration. Based on data from China’s listed companies from 2011 to 2024, this paper focuses on the peer effect of data factor application and systematically examines its impact on corporate green technology diffusion. The findings indicate that there is a significant industry peer effect in data factor application, which can effectively accelerate corporate green technology diffusion. Heterogeneity analysis reveals that for enterprises with stronger market power or with more developed digital infrastructure, the peer effect of data factor application more significantly enhances the promotion of corporate green technology diffusion. Mechanism testing indicates that this peer effect accelerates green technology diffusion through three pathways: enhancing R&D collaboration levels, boosting innovation absorption capacity, and facilitating the flow of technical information channels. The moderation effect analysis indicates that the marketization of technological factors, green industrial clusters, and intellectual property protection all exert positive moderating effects on the relationship between the peer effect of data factor application and corporate green technology diffusion. This paper examines the behavioral consequences of the peer effect of data factor application and deepens the theoretical understanding of how external environments affect corporate green innovation decisions. It not only expands the theoretical perspective on the driving mechanisms of green technology diffusion, but also provides valuable practical guidelines for enterprises to accelerate green technology diffusion through data factor application.