In this paper, a method for Integrated Energy System (IES) planning with reliability and economy is proposed to solve the problem of airport IES planning. Firstly, the structure model of the airport’s IES is established based on the analysis of airport energy demand. Next, combined with the airport power distribution design specification, the reliability constraint model of the airport IES is given, and the reliability constraint model is solved by scenarios, and then the capacity constraints of the energy equipment of the IES are obtained. Finally, under the constraint of reliability, the total cost of the IES during the life cycle is taken as the goal, an economic optimization model is constructed, and the 0-1 mixed integer linear programming method is used to solve the proposed optimization model. The simulation results show that the solved IES can meet the energy demand of the airport. And the proposed planning method is universality and scalability.