The best way and technical path of optimizing the primary energy structure is studied, so as to provide reference for China's energy optimization development and technical innovation. Based on the analysis of current situation and trend of global energy development, it has taken theoretical innovation as the breakthrough point, established the energy-brain model, put forward the concept of energy life-cycle, studied the ways to optimize the energy system, as well as analyzed and discussed the technical demand and technical path of energy optimization in China. It has revealed that the energy industry can work as a closed-loop system, pointed out that optimizing primary energy through secondary energy is the most convenient and effective way to optimize the energy system and extend the energy system life-cycle. Furthermore, electric energy is the best choice of secondary energy to optimize primary energy. It has concluded that through the technical innovation in three directions of primary energy to electric energy conversion, electric energy transmission, energy storage & Energy Internet, and the continuous and stable supply of electric energy can be ensured. Meanwhile, the energy system life-cycle can be extended, and the clean, low-carbon, safe and efficient energy system can be built more efficiently.