Most existing studies on energy sustainability have focused on qualitative research. Few studies have applied quantitative methods, and there has not been a systematic review of energy sustainability. To fill this gap, this study first developed a sustainable energy evaluation index system consisting of 20 indicators across the three dimensions of economy, energy, and environment based on the pressure-state-response (PSR) model. The weights of these indicators were then determined in conjunction with the weighting method. Finally, the matter-element extension method was improved to quantify energy sustainability. The proposed method was applied to evaluate China’s energy sustainability status from 2000 to 2015. The results show that China’s status continued to improve; however, it remained at a low level. To improve China’s energy sustainability, more efforts are needed in the economic, energy, and environmental dimensions.