<p>Digital technologies are increasingly deeply intertwined with the real economy, triggering profound transformations in the socio-economic system and ecological environment. It is important to explore the influence of input digitalization (ID) on carbon emission intensity (CEI) so as to more effectively attain the carbon neutrality goal. In this paper, we employ the world input–output database (WIOD) and high-dimensional fixed-effect models to examine the correlation between ID and CEI as well as its underlying influencing mechanisms at the global industry level. The empirical findings reveal that ID significantly augments CEI, and this remains valid even after eliminating extreme values, substituting key variables, and applying instrumental variables to address endogeneity. The mechanism analysis indicates that ID impacts CEI via the channels of energy scale, energy structure, and energy efficiency, with the energy scale mechanism playing a preponderant role. The heterogeneity analysis shows that the impact of ID on CEI is more pronounced after the financial crisis, in the Asia–Pacific region, and in labor-intensive manufacturing, household services, and agriculture-related industries. This paper offers solid empirical evidence and a valuable decision-making reference at the global industry level for better curbing carbon emissions and realizing carbon neutrality targets in the digital age.</p>