Energy and environmental problems are among the important factors restricting economic development. The development of green energy is an important measure to deal with energy and environmental problems, such as wind energy and photovoltaic. Energy Internet is an important mean to promote the transformation of the energy structure, improve energy efficiency and reduce pollution. In introduction, the energy Internet is put forward. Then the architecture and characteristics of energy Internet, such as integration, openness, intelligence and marketization of energy Internet are analyzed. Next, key technologies such as energy router, virtual power plant and network security technology are discussed. Finally, a few suggestions for the development of energy Internet are proposed, and hoped to promote the development of energy Internet.