Drawing upon Chinese A-share listed companies from 2009 to 2021 as research sample, the impact of digital transformation on firms' sustained green innovation was explored. It is found that digital transformation significantly promotes firms' sustained green innovation inputs and outputs, and this conclusion still holds after a series of robustness tests. Heterogeneity analyses results indicate that the contribution of digital transformation to firms' sustained green innovation varies according to the nature of firms' property rights and the type of industry. The role of information asymmetry, and investor focus in this relationship was further analyzed. The results show that information asymmetry partially mediates the effect of digital transformation on firms' sustained green innovation, while investor focus play a moderating role.