In China, rapid development has lead to serious environmental pollution. Excessive carbon dioxide emissions have not only caused significant damages to the environment, but also harmed people’s health. Subject to carbon peaking and carbon neutrality goals, cities need to conserve energy and reduce emissions while maintaining steady economic growth, an effective measure for which is to improve carbon efficiency. Carbon efficiency is affected by environmental regulation. As a kind of environmental regulation featuring public participation, environmental information disclosure has become an important measure affecting carbon efficiency. In this paper, we estimated carbon efficiency of Chinese cities with super-efficiency DEA model, analyzed the spatial and temporal heterogeneity of carbon efficiency. Unlike previous literature, we further investigated the impact of environmental information disclosure on carbon efficiency using difference-in-differences model, tested split samples by geographical location and city size to examine the impacts of environmental information disclosure on carbon efficiency in different regions and cities of different sizes, and validated that environmental information disclosure affects carbon efficiency through technological improvements and clean industry substitution. On this basis, we proposed policy measures to improve carbon efficiency, including transforming government functions, offering inter-regional carbon compensation, and establishing a diversified carbon emissions reduction system.