Regional carbon emission efficiency is one of the key factors affecting China to achieve the goals of carbon peaking and carbon neutrality. Accurately measuring the carbon emission efficiency of different regions is the basis for promoting regional collaborative governance under the guidance of dual carbon goals. In order to measure regional total factor carbon emission efficiency, an evaluation method of regional carbon emission efficiency was developed based on the SBM (Slack-based measure, SBM) model considering unexpected output and relaxation variables. The characteristics and temporal and spatial changes of carbon emission efficiency were then evaluated at China's provincial level. Based on the above results, policy recommendations for regional carbon emission reduction and collaborative governance were put forward.