This study constructs an index on synergy of corporate carbon reduction, pollution reduction, and green expansion (PCG), and uses a difference in difference model to test the impact of digital government (DGO) on PCG. Results show that DGO significantly promotes PCG, and compared to companies without DGO, DGO can lead to a 2.4% increase in PCG. And, DGO may promote PCG by increasing environmental information disclosure, environmental subsidies and environmental regulations. In the heterogeneity, DGO has a higher promoting effect on PCG in eastern enterprises, heavily polluting industries, and state-owned enterprises. Furthermore, digital financial support, media supervision, and public participation will promote the positive effect of DGO on PCG. This study aims to provide implications for promoting PCG and empirical reference for promoting DGO.