Air volume control method and device of washing and drying equipment and washing and drying equipment

The invention provides an air volume control method and device of washing and drying equipment and the washing and drying equipment. The washing and drying equipment comprises a washtub and a clothes washing and drying machine, and the washtub and the clothes washing and drying machine share a fan for providing air for the washtub and providing drying air for the clothes washing and drying machine; an air outlet of the fan is communicated with a first air duct leading to an air supply outlet of the clothes washing and drying machine and a second air duct leading to an air blowing opening of the washtub; the first air channel is provided with a first wind shield used for controlling the air inlet amount of the clothes washing and drying machine, the second air channel is provided with a second wind shield used for controlling the air inlet amount of the washtub, and the method comprises the steps that in response to the working mode, selected by a user, of the washtub, the second wind shield is controlled to b