Abstract: Integrated electricity-gas system（IEGS） based on bi-directional coupling of gas turbine and power to gas（P2 G） is an important carrier to realize accommodation of high-proportion renewable energy and improve terminal energy utilization efficiency.Firstly, based on the comparison of transmission characteristics of power system and natural gas system, the connotation,characteristics and advantages of IEGS are described. Secondly, the technical principle and modeling method of P2 G in IEGS are introduced. Furthermore, the research progress of relevant technology is emphatically summarized from two dimensions: solution of IEGS energy flow model and optimization of IEGS operation scheduling. In terms of research on optimal operation scheduling,it is discussed from five aspects, including basic scheduling model and consideration of system randomness, energy flow difference and market operation mechanism and non-linear processing method of model. Finally, the prospect of future research on IEGS modeling and operation optimization are proposed.