Given the finite nature of fossil fuels and their adverse environmental impacts, establishing a new sustainable energy system has become an urgent issue today. In order to reduce the carbon emissions of integrated energy systems(IES) and optimize the operational costs, this paper proposes an optimized scheduling of comprehensive energy systems considering both economic and environmental factors to meet the demand for renewable energy generation regulation and improve energy utilization efficiency. In the paper, a comprehensive demand response model of user energy consumption behavior is first constructed to ensure the safe operation of the power system. Based on this model, a joint operation model of Power-to-Gas (P2G) and Carbon Capture and Storage (CCS) systems, as well as operational constraints of natural gas and hydrogen mixed P2G devices, are considered. By introducing a carbon trading mechanism and minimizing total costs as the objective, a day-ahead low-carbon economic scheduling model for the system is established. To address the uncertainty of customer demand response, robust optimization theory is adopted, and the problem is reformulated as a linear programming problem using duality theory for solution using commercial solvers. Simulation results demonstrate that this scheduling strategy can improve the economic benefits of power plants while reducing renewable energy consumption and power plant risks, promoting the sustainable development of integrated energy systems. This day-ahead economic scheduling strategy for integrated energy systems is of great significance for constructing a low-carbon, efficient energy system.