The present disclosure relates to an intelligent positive and negative pressure system and an operation method therefor, and an intelligent positive and negative pressure electric appliance. The system comprises a positive and negative pressure intelligent fresh-keeping refrigerator, a positive and negative pressure intelligent washing machine, a positive and negative pressure dish washing and fruit and vegetable cleaning machine, a positive and negative pressure range hood, a positive and negative pressure baking and frying microwave oven, a positive and negative pressure fresh-keeping compartment container, a positive and negative pressure fresh-keeping warehouse, a positive and negative pressure disinfection machine, and a positive and negative pressure module cabinet. By means of the positive and negative pressure system, a fluid and a carried substance thereof are regulated and controlled by means of positive and negative pressure, so as to affect an object in a specific space in a targeted manner.