This paper uses DEA and input/output model to study their overall energy efficiency, variance and causes among 23 resourcesexhausted cities based on their 2010-2014 data, with results showing a general energy efficiency, but variable with areas. Energy efficiency is positively related to economy, high in developed area. In 2014, 50% of the resourcesexhausted cities are at rising their return stage, leaving big room to improve their energy use efficiency. Some cities bear input redundancy, which need to improve their energy efficiency.