The digital industry and the energy industry are the two primary forces behind contemporary economic and social progress, and their convergence development is the necessary path to realizing carbon peak and carbon neutrality goals. The paper measures the level of convergence of the digital industry and energy industry (CDIEI) and empirically examines its relationship with China’s 30 provinces’ carbon emissions (CE) between 2012-2021. Considering the differences in geographical location and industrial convergence level, the heterogeneity of the CDIEI on CE was analyzed. The intrinsic influence mechanism and nonlinear effects of the two were deeply explored. The results indicated that the CDIEI can reduce CE, which was further corroborated by several robustness checks. The carbon reduction effect of the CDIEI is more significant in the central and eastern regions, as well as in high convergence areas. The CDIEI can curb CE by stimulating industrial structure upgrading (ISU) and boosting green technology innovation (GTI). When ISU and GTI cross a single threshold, the CDIEI can significantly curb CE. The study’s findings offer reference value for raising the CDIEI and minimizing CE immediately.