Improving the utilization rate of clean energy and reducing the carbon emissions of energy systems are important means to achieve the low-carbon transformation of energy structure and the goal of "double carbon". Based on this background, a low-carbon economic dispatching method of integrated energy system including wind power, electric energy storage, gas turbine, carbon capture equipment and thermal storage solar power station under the step-by-step carbon trading mechanism was proposed. Combined with the response strategy of flexible resources on the load side, the dispatching potential of integrated energy system in economic operation and low-carbon environmental protection was explored from the joint dispatching of source and load. Finally, with the minimum total cost of system operation as the optimization objective, CPLEX commercial solver was used to solve multiple scenarios. The results show that the source-load coordinated scheduling method proposed can effectively reduce the system carbon emissions and improve the system operation efficiency.