China’s energy policy has gone through three stages：self-sufficiency，diversification and complementarity，and then conservation and efficiency. To the request to accelerate the construction of a modern energy system during the 14th Five Year Plan period to the proposal to accelerate the planning and construction of a new energy system in the report of the 20th National Congress of the Communist Party of China，the achievements of green and low-carbon transformation in China’s energy system have been demonstrated. Starting from the evolution of China’s energy policy and the proposal and connotation of a modern new energy system，this article clarifies the relationship between the modern energy system and the new energy system，analyzes the significant challenges of energy strategy，institutional mechanisms，technological innovation，and supply and demand consumption. By leveraging supply and demand to build a diversified energy supply system，layout the cross-regional channels and base construction of the new energy system，this paper establishes a mechanism for tackling core technologies，and enhances the digitalization and intelligence level of the new energy system. The new energy system not only emphasizes the low-carbon and green nature of the system，but also pays more attention to the dual logic of coordinated development and security. Under the target requirements of “carbon peak carbon neutrality” and “new development stage，new development concept”，it will develop from the supply side，technology side，consumption side and system side to build an implementation path in the new power system.