In the context of the new power system, the growing wind-solar access scale and increasingly complex demand side load types brought new challenges. In an attempt to enhance the ability to couple and convert multiple energy sources of integrated energy system to match the supply-demand relationship between the source and load, a collaborative optimal scheduling model of multi-region integrated energy system (MRIES) considering the integrated demand response (IDR) is proposed in this paper. The IDR load model and IDR cost-income model considering multiple adjustable loads are established. The energy flow topology of the MRIES with energy flow direction of "source-input energy node-energy hub-output energy node-terminal load" is constructed, and its energy coupling matrix is set up. On this basis, the optimal model of MRIES is established considering the interaction of regional electricity and energy to minimize the total cost of the system. Through the comparative analysis of several scheduling schemes on typical days in winter and summer, it is proved that the proposed model can enhance the multi-energy coupling conversion capability, and thus effectively improve the overall economy, flexibility and reliability of the system.