Abstract: The establishment of an integrated energy system（IES） that considers both the quality and quantity of energy is one of the most important measures to promote energy transition.Traditional energy flow and energy efficiency studies focus only on the“quantity”of energy,while ignoring the“quality”of different energies,which does not fully reflect the value of energy and has limitations in application.This paper presents the concept of the high-exergy integrated energy system（HE-IES）.The focus is on the enhancement of the delivery capacity of effective energy in the IES.Based on the exergy flow mechanism model of the IES and the core parameters of the system energy quality,this paper discusses the exergy flow model for power systems,natural gas systems,thermal systems,energy stations,and renewable energy.Then,the key research contents and typical mathematical models of the HE-IES in the planning,operation optimization and energy dispatching,and the trading and market-based mechanism are discussed in depth.Meanwhile,the prospects are given on the future research directions for the HE-IES.