Customer-side integrated energy system (C-IES) is an important direction of energy consumption in the future. The optimization of C-IES operation can improve the economic and environmental benefits. For this purpose, an energy transaction model for C- IES composed of multiple distributed energy stations (DES)and energy users (EU) is established, and distributed game equilibrium strategy for C- IES based on demand response is proposed.DESs aim to maximize their respective benefits, while EUs aim to maximize their respective utility. Firstly, the initial problem is decomposed into the demand response optimization problem of multiple subsystems through dual decomposition. Then distributed solution is implemented for the demand response optimization problem of each subsystem. The main advantage of this method is that the two sides of the energy transaction do not need a central controller or any third party, and the privacy of DESs and EUs is guaranteed.Finally, the effectiveness of the proposed distributed game equilibrium strategy is verified by a numerical example.