The purpose of this study is to improve the energy-saving effect of various energy-saving ways. To this end, this paper studies the calculation and optimization for the energy-saving effect of China’s energy conservation and consumption reduction methods. Firstly, based on E-G cointegration and Granger causal analysis, this paper analyses the relationship between China’s economic growth and energy consumption. Then, the system dynamics model was used to simulate China’s energy economic system, and analyse the energy saving effect of China’s energy conservation and consumption reduction methods. Studies show that technological progresses have caused China’s industrial unit energy consumption to fall by an average of 4.26% per year, and energy intensity also decreases in certain degree. Therefore, to achieve scientific development in China, energy conservation and consumption reduction are top priorities now, and there may be a certain surplus in energy industry capacity.