The performance of the air conditioning system under partial load is affected by its control method and strategy. This paper established the air conditioning system mathematical model and constructed the experimental device to verify it. Based on the established air conditioning system model,the system performance under partial load was studied when the chilled water flow,cooling water flow,cooling tower air volume and the air volume of the air conditioning box were varied and controlled. At the same time,the parameters for the priority of the system regulation and energy-saving potential were obtained. On this basis,the paper studied and acquired the energysaving strategy and energy saving potential under comprehensive regulation of the system. The results showed that the energy saving rate can reach 11.7% by using system global control at the load rate of 0.6.