Abstract: In this paper we aim to enhance the consumption capacity of the photovoltaic and wind power in the integrated energy system, improve the utilization efficiency of various energy sources in the system, and realize energy conservation, emission reduction and low-carbon economic dispatch. Firstly, considering the flexible dispatching characteristics of flexible load on the demand side, an optimal scheduling model with flexible demand response on the load side taken into account is established based on the transferable and reducible characteristics of electricity, gas, cold and heat on the user side. Secondly, a two-stage P2G unit is introduced to increase the coupling degree of various energy sources within the system. Finally, considering that the reward-penalty ladder carbon trading mechanism and the green certificate trading mechanism participate in the optimal scheduling of the system, ,a low-carbon economic scheduling model of integrated energy system with two-stage P2 G considering green certificate trading and load-side flexible demand response is constructed, with the lowest total operating cost of the system as the objective function. After linearization, the model is compiled using YALMIP toolbox in MATLAB and solved by CPLEX solver. The operation results of the system in four different scenarios are analyzed to verify the effectiveness of the model in reducing carbon emissions and the total cost of system operation, which has certain engineering practical significance.