This paper analyzes the necessity of developing energy internet from the perspective of the analysis of electric power utility, then discusses the basic features and demonstration prospect of energy internet.Reasonably restricting the scale of synchronized power systems, using VSC back-to-back HVDC to separate multiple AC regional power systems, and constructing multi-terminal flexible HVDC meshed network among multiple AC regional power system are the features of energy internet on the level of power transmission.The local active distribution system and VSC-DC distribution system with multi-energy interconversion is the physical foundation of energy internet on the level of power distribution, in which the generalized demand response and local energy trading platform can achieve the commercial operation of energy internet.This paper proposes that constructing the advanced information communication network and new energy trading system and using them as ties of brand-new energy comprehensive utilization architecture are the demonstration roadmap of energy internet.