To further improve the operational flexibility and low-carbon emission capacity of integrated energy system (IES), a low-carbon optimal scheduling model of IES coupled with a solvent-storage carbon capture system (CCS) and an organic Rankine cycle (ORC) waste heat power generation device is proposed. Firstly, a combined heat and power (CHP) model for a gas turbine (GT) is constructed through waste heat utilization, and an ORC waste heat power generation unit is introduced to achieve thermoelectric decoupling of the unit and improve the operational flexibility of the system. Secondly, the carbon emissions of the system are constrained through the CCS, and the carbon reduction capability and flexible carbon control advantages of the solvent-storage CCS are further validated. Finally, a day-ahead optimal scheduling model is established with the objective of minimizing the total cost of the system, including energy procurement cost, carbon emission cost, and renewable energy curtailment cost. The results show that the ORC waste heat power generation unit achieves thermoelectric decoupling of the unit and enhances the operational flexibility of the system, while reducing operational costs and carbon emissions by 1.06% and by 1.03%, respectively. The solvent-storage CCS reduces the carbon emissions and total costs of the system by 77.91% and 11.84%, respectively, and the utilization rate of renewable energy reaches 75.48%. The simulation results demonstrate that the proposed model can effectively lower system operating costs, reduce carbon emissions, and promote renewable energy integration.