The invention discloses a control method for an air conditioning system, and belongs to the technical field of air conditioning. The air conditioning system comprises multiple air conditioners mountedat different indoor areas. The method comprises the steps that one or more work parameters of each air conditioner are obtained; the multiple air conditioners are divided into two groups; and besides, the air conditioner group meeting the preset conditions is set as the first air conditioner group, and the other air conditioner group is set as the second air conditioner group. By adopting the method disclosed by the embodiment of the invention, the indoor temperature is detected in real time, when the indoor temperature meets the preset conditions, the multiple air conditioners are controlledto be networked, and the operation states of the multiple air conditioners are cooperatively controlled to achieve air exchange; and the multiple air conditioners cooperatively work, the flowing amount of indoor air is increased, the effectiveness of air exchange is guaranteed, and the influence on the refrigerating or heating effect is reduced. The invention further discloses a control device for the air conditioning system.