Clarifying the temporal and spatial characteristics of regional carbon emissions and low-carbon efficiency is of great significance for the realization of carbon peaking and carbon neutrality. This study calculated the carbon emissions in Sichuan Province from 2015 to 2022 based on four major units: energy activity, industrial production, forestry activity, and waste disposal, and its time evolution characteristics and key sources were investigated. Meanwhile, based on the Super-SBM-Undesirable model, the low-carbon efficiency of Sichuan Province and its 21 cities (states) was evaluated, and its spatial heterogeneity characteristics were investigated. The empirical results reveal the following: (1) energy activity was the main contributor to regional carbon emissions, with thermal power generation and industrial energy terminal consumption as the key sectors. Inter-regional power allocation could indirectly reduce the regional emission intensity. The carbon emissions of industrial production showed significant aggregation in cement and steel production. The forest carbon sink had a significant effect on alleviating the regional greenhouse effect. The carbon emissions of waste disposal were small. (2) From 2015 to 2022, the low-carbon efficiency of Sichuan Province showed an overall upward trend. Chengdu had a high level of economic development, a reasonable industrial organization, and a continuous increase in its urban greening rate. Heavy industrial cities such as Panzhihua and Deyang made great efforts to eliminate backward production capacity and low-carbon transformation of key industries. Therefore, they were the first mover advantage regions of low-carbon transformation. Zigong, Mianyang, Suining, and Leshan enjoyed favorable preferential policies and energy-saving space, and were developmental regions of low-carbon transformation. But they need to actively deal with the problem of industrial solidification. The low-carbon efficiency of plateau areas in western Sichuan was relatively low, but they have unique resource endowment advantages in clean energy such as hydropower, so the development potential is strong. Cities such as Ya’an and Bazhong faced a series of challenges such as weak geographical advantages and the risk of pollution haven. They were potential regions of low-carbon transformation.
