Building an energy superpower is a major development strategy for China at present and long-term goal for other countries. This study aims to propose an ideal evaluation system, and construct a quantifiable index for energy superpower. 7 weight allocation schemes and 16 weight sets were employed to test the impacts of different weights on energy superpower index (ESPI), ensuring authenticity, rationality, and accuracy, and finally the subjective entropy weight method was adopted to determine the weights. The ESPI of 11 economies, including China, the United States, Canada, Russia, Australia, Germany, Japan, the United Kingdom, South Korea, Argentina, and the European Union, was computed for a period of 21 years (2000−2020). China's index demonstrated a remarkable increase from the second-to-last place in 2000 to second place in 2020, surpassing the other 10 countries. The United States and Argentina's energy superpower indices consistently ranked first and last respectively from 2000 to 2020, while the early European Union's index ranked second, but was later surpassed by China, falling to third. The energy superpower indices of Canada, Russia, Australia, Germany, the United Kingdom, Japan, and South Korea share similar values with slow growth rates, roughly ranking in between the European Union and Argentina.