Abstract: In the context of the "dual carbon" targets and large-scale renewable energy integration,the flexible adjustment capabilities of coupling devices such as gas-fired units,P2G,and combined heat and power units are gradually being explored,which have also enhanced the coupling of power systems,natural gas systems,and district heating systems. Therefore,the traditional independent scheduling mode may not be applicable. The coordinated scheduling of integrated electricity-gas-heat systems（IEGHS）is an important means to improve energy utilization efficiency and respond to the uncertainty of new energy.The commonly used energy flow models and coupled device modeling for three types of energy systems in optimization scheduling research are analyzed.The current research progress is reviewed from the aspects of coping with renewable energy uncertainty,model of coupling system,optimization solution algorithm and security region of IEGHS.Finally,the challenges of the current IEGHS studies are summarized,and an outlook on the direction of subsequent research is given.