This study adopts the A-share listed companies in Shanghai and Shenzhen from 2007 to 2021 as the research sample. The impact and internal mechanism of enterprise digital transformation (DT) on supply chain commercial credit financing is investigated. The higher the degree of DT of enterprises, the higher the increase of commercial credit financing obtained from upstream suppliers, and a series of robustness tests confirm the existence of this relationship. The mechanism test finds that DT increased supply chain commercial credit financing through three channels: improving enterprise information transparency, promoting enterprise supply network diversification, and improving market expectations. Heterogeneity analysis reveals that when the degree of financing constraints of enterprises is high and the level of marketisation in the region is low, the promotion of enterprise DT on supply chain commercial credit financing is more significant. This study provides direct empirical evidence for the impact of enterprise DT on supply chain commercial credit. Additionally, it enriches the relevant research on the economic consequences of enterprise DT and the factors affecting commercial credit financing.