Abstract: Because of the intermittent, volatility and randomness features of wind power, the flexibility of integrated energy system and the energy conversion ability between power system and natural gas system is an essential condition to consume large scale wind power. Since CHP (combined heat and power) unit and GF (gas furnace) are widely used and P2G (power to gas) technology is introduced, it had a great effect on different types of energy services, including electricity, gas, and heat. This paper puts forward an integrated energy system expansion planning model considering the coupling of power system, gas system and thermal system during the planning period. Based on the curve of load duration and wind intensities, by using the scenario method to illustrate the uncertainty of wind power and load, then a mathematical model for dynamic coupling between gas and electricity of integrated energy planning that can consider wind power, P2G and CHP unit at the same time is built. The model minimize the investment cost and operation cost during the planning period, which is constrained operation safety and coupling relationship of power system and gas system, determining the optimal planning scheme for wind turbines, thermal power unit, transmission lines, gas transmission lines, CHP, GF, P2G. To achieve a balance between efficiency and precision, a series of linearization method is adopted to solve the model. Simplified mathematical model is a mixed integer linear programming model, which is programmed on GAMS software and call on the CPLEX solver to solve the model. 6 nodes gas and electricity coupling test system is utilized to analyze and compare the cases. Case studies validate the effectiveness and superiority of the model in the paper.