In order to achieve the strategic targets of carbon peak and carbon neutrality in China, it is urgent to explore the low-carbon and efficient utilization of renewable energy. The cogeneration unit challenges the consumption of renewable energy with the working mode of combined heat and power. Therefore, the collaborative operation framework of power-to-gas, carbon capture system, distributed generation and combined heat and power unit is proposed and its coupling characteristics are analyzed. An optimal scheduling model of integrated energy system based on this framework is constructed, and a user demand response model is established. Then, taking the integrated energy system side as the upper optimization model subject, and the user side as the lower optimization model subject, a bi-level optimization model based on master-slave game is proposed, as well as its solution method. The example shows that the model and strategy proposed in this paper can not only effectively improve the consumption of renewable energy, reduce the carbon emissions of cogeneration units, but also reduce the operation cost of the system and the energy purchase cost of users, and improve the energy use efficiency of users and the economic benefit of the system.