Abstract: Energy internet is a smart integrated energy system that can solve current energy problems and promote the transformation of energy system, and it is of great significance in increasing the proportion of renewable energy, promoting the clean and efficient use of fossil energy, and improving the overall efficiency of energy. The integration of power system and cyber-physical system is the core foundation for building energy internet, and the integration level is an important factor for determining the development stage of energy internet. Based on a study of the value and framework of power and cyber system integration, as well as its relationship with energy internet, a quantitative analysis is made for a long historical period (1900-2018) to reveal the law of development for power and cyber system integration, and predict the development trend and bottlenecks in future, and the key strategic direction is proposed for energy construction, which can provide a theoretical basis and decision-making reference for the construction and development of energy internet in China.