The variable air volume (VAV) air-conditioning system with its superior energy saving effect has been applied in many developed countries, also drawn more and more attention in China. Due to the characteristics of VAV air-conditioning system are nonlinear, large time lag, strong coupling, multi-variable and multi-disturbance, the control complexity of the VAV system increase greatly. The energy conservation and comfort of the VAV air-conditioning system can not fully been embodied in application. The research on the VAV system has become the hot spot in the science and technology workers, many new methods and strategies have emerged. From the three aspects: the air system, the water system and the large scale system, the paper describes the control strategies, the control methods and the research progress about the VAV air-conditioning system.