The invention relates to a temperature and humidity control process and an air conditioning system for a high-bay depot of a cigarette factory. The air conditioning system comprises a first air conditioning unit (1), a second air conditioning unit (2), a top layer air duct array (4), a bottom layer air duct array (5), the high-bay depot (6) and a temperature and humidity detection device (7); air-supply and air-return switch devices (3) are arranged between the first air conditioning unit (1) and the second air conditioning unit (2) and between the top layer air duct array (4) and the bottom layer air duct array (5) respectively, and target requirements for controlling temperature and humidity of a high-bay depot area is achieved by changing air paths through the air-supply and air-return switch devices (3) according to results of the temperature and humidity detection device (7) and process control requirements. The air conditioning system can be flexibly applied to the temperature and humidity control of the high-bay depot of the cigarette factory in different areas and under different seasons and climate conditions, the process design requirements can be achieved, the running energy consumption can be effectively reduced, and the energy-saving and consumption reduction effects can be achieved.