China's manufacturing sector accounts for 36 % of the nation's total carbon emissions. Managing manufacturing's carbon intensity is crucial for achieving China's carbon neutrality objectives. However, the difference in carbon intensity levels within the manufacturing sector has been less examined, which prevents the formulation of targeted policies. Among the various options to tackle the issues, the growing information and communication technology (ICT) infrastructure is predicted to boost the digitalization of manufacturing industries and reduce carbon intensity. The study measures the inequality of carbon intensity and explores the ICT infrastructure's effect on carbon intensity using manufacturing industry data for 30 provinces from 2001 to 2016. We use the Dagum Gini coefficient to measure the inequality of carbon intensity and find that the carbon intensity inequality of manufacturing has continuously increased over the years. Results reveal that inter-regional differences are the major contributor. Moreover, our results indicate a national convergence of manufacturing carbon intensity using the spatial β-convergence method. In addition, we find that ICT infrastructure hinders the national convergence of carbon intensity, but it varies across regions and sectors. Thus, we recommend that the government consider regional and sectoral heterogeneity when setting emission reduction targets and planning ICT infrastructure development.