Abstract: In order to effectively reduce the economic costs while the integrated energy system meets various load requirements, a two-level optimal configuration algorithm aiming at economy is proposed in this paper, and the optimal configuration of an island integrated energy system is studied. Firstly, the combined hydrogen, heat and power system (CHHP) is built, and the overall objective function of the system is established considering the operation and maintenance, purchase of the equipment and the aging of fuel cells, electrolytic cell and batteries. Then, the capacity of energy equipment is configured by the two-layer optimization configuration algorithm adopting the grey wolf optimization sine cosine algorithm (GWO-SCA) on the upper layer and the mixed-integer linear programming (MILP) on the lower layer. Finally, examples are used to verify the superiority of the algorithm. Various charging modes are considered for the electric vehicle load in the system, and the effects of different charging modes on the configuration results and economic cost are discussed. The results show that the proposed optimal configuration method can realize the economic and stable operation of the integrated energy system.