Abstract: Under China’s carbon peaking and carbon neutrality goals, the integration of digital platforms and green manufacturing has become a key pathway for industrial transformation. However, the spatial heterogeneity of their relationship and the underlying mechanisms remain insufficiently explored. Using panel data from 31 provincial-level regions in China (excluding Hong Kong, Macao, and Taiwan) during 2014–2023, this study constructs a composite index of digital platform development and quantifies green transformation in manufacturing using the Epsilon-Based Measure (EBM) model and the Global Malmquist-Luenberger (GML) index. GIS analysis is used to characterize spatiotemporal patterns, while two-way fixed-effects, mediation, and heterogeneity models are employed to examine the effect, transmission mechanism, and regional differences. The results show that: 1) both digital platform development and green transformation in manufacturing exhibit pronounced spatial differentiation. Digital platform development shows a pattern of eastern leadership, central rise, and western catch-up, while green transformation in manufacturing shows a fluctuating upward trend, increasing by 22.67% from 2014 to 2023, with its spatial pattern evolving from localized coastal concentration toward a nationwide multi-polar structure; 2) digital platform development significantly promotes green transformation in manufacturing, with a coefficient of 0.678, while innovation vitality plays a significant mediating role, with an indirect effect of 0.430; 3) among the three dimensions of digital platform development, infrastructure has the largest estimated coefficient, and the estimated effect of digital platforms is larger in regions with lower levels of green transformation. From a geographical perspective, these findings clarify how innovation vitality and regional development conditions shape the relationship between digital platforms and green transformation, providing empirical support for differentiated digital and green transformation strategies across regions.