A new model is proposed for the optimal scheduling of gas-electric integrated energy systems, considering the incentive demand response (IBDR) to provide the reserve ancillary service. By incorporating the IBDR, one hand, the system can give full play to the complementary functions of different energy sources to enhance the efficiency of the system; on the other hand, more flexibility can be utilized to cope with the uncertainty of wind power with IBDR providing reserves with conventional units simultaneously. We establish the IBDR model with segmental price-quantity curves, and the transient gas flow and steady state power flow are combined to formulate the operation model of gas-electric integrated systems. A 6-node power network and a 12-node natural gas network were selected to construct a gas-electric integrated energy system. The simulation results show that the IBDR can improve the flexibility of the system and decrease the total operation cost of the gas-electric integrated energy system.