Abstract: To enhance the economy of regional integrated energy system and improve the accommodation ability of renewable energy sources, a scheduling optimization model containing power-to-gas (abbr. P2G) was proposed. Firstly, the P2G was divided into two operating stages: in the link of water electrolysis the produced hydrogen was added into hydrogen storage tank as the fuel source of hydrogen fuel cell, and the energy conversion of hydrogen energy into electric energy and thermal energy was implemented by hydrogen fuel cell, in the next link the residual hydrogen was input into methanator to reduce the energy loss due to directly methanating all hydrogen. Secondly, the gas turbine units adopted the variable efficiency operation mode, by means of flexibly regulating the efficiency of power supply and thermal supply of gas turbine units the output of heat and electricity became more economic and reasonable. On this basis, taking the minimum daily operating cost composed of system electricity purchasing cost, gas purchasing cost, wind curtailment cost and environmental cost as economic objective, a day-ahead optimization scheduling model for of regional integrated energy system containing P2G was constructed. Finally, this problem was solved by chaotic particle swarm optimization algorithm based on spatial distance. Simulation results show that the proposed scheduling model can effectively promote the reasonable and high-efficient utilization of multi-class energy sources and improve the accommodation ability of renewable energy sources and the economy of system operation.