Central air conditioning load has become the main component of peak load, alleviating peak load by central air conditioning has become an effective mean. Firstly, the central air conditioning system is analyzed, the control mode combining with the start-stop control and flexible control of the central air conditioning is established, and the potential of the central air conditioning is analyzed combined with the indoor thermal process model. The parameters of virtual charge- discharge power, virtual energy storage capacity and virtual energy storage state are obtained. The differences between different control modes are described by virtual energy storage charge-discharge efficiency, and the central air conditioning model is transferred to virtual energy storage model.Based on the virtual energy storage model, a peak adjustment strategy for virtual energy storage group is proposed to reduce the peak load as far as possible to the planned load reduction. The simulation results verify the effectiveness of the peak adjustment strategy.