Under the background of ‘double carbon’, the combination of carbon trading and green certificate trading mechanism can better reflect the development of low-carbon economy in integrated energy system. Therefore, a thermoelectric optimal scheduling strategy for integrated energy system considering high proportion of new energy carbon-green certificate is proposed. First of all, the introduction of step-by-step carbon trading, considering the CET, GCT, CCER interaction mechanism, guide IES to control carbon emissions. then, a new type of CHP with CCS and P2G adjustable heat-to-electric ratio is proposed, which gives priority to the use of abandoned air volume to supply the required electricity, thus improving the consumption capacity of high-proportion new energy and further improving the low carbon and economy of IES. Finally, the rationality of this paper is verified by calling the CPLEX solver to solve the different model cases.