This study explores the impact of supply chain digital transformation on corporate carbon emissions. Utilizing a Propensity Score Matching-Difference in Differences (PSM-DID) approach and a sample of A-share listed companies in China from 2010 to 2021, we assess the effect of supply chain digitalization policies on corporate carbon emissions. The findings reveal that supply chain digital transformation contributes to reducing corporate carbon emissions, a conclusion supported by both baseline regression analysis and robustness checks. Further mechanism tests uncover the internal and external mechanisms through which supply chain digital transformation lowers carbon emissions, highlighting the crucial roles of enhanced corporate governance and support from governments and industry organizations. Additionally, heterogeneity tests indicate that non-state-owned enterprises exhibit more pronounced carbon reduction effects in the process of supply chain digital transformation. In summary, supply chain digital transformation emerges as an effective pathway to reduce corporate carbon emissions. Governments and businesses should strengthen cooperation to promote its in-depth implementation, thereby achieving more environmentally friendly and sustainable development goals.