The invention relates to a positive-negative pressure system, an operation method thereof and a positive-negative pressure electric appliance using the system. The positive-negative pressure electricappliance comprises: a positive-negative pressure refrigerator, a positive-negative pressure washing machine, a vacuum dish washing and fruit-vegetable cleaning machine, a super-oxygen washing range hood, a positive-negative pressure oven fryer microwave oven, a positive-negative pressure fresh-keeping compartment, a positive-negative pressure fresh-keeping warehouse and a positive-negative pressure module cabinet. According to the technical principle and the basic operation method of the positive-negative pressure system, air flow is regulated and controlled through positive and negative pressure, or multiple effective loads like ozone, air catalysts, negative ions, air-conditioned gas and water are carried for orderly getting in and out of the positive-negative pressure cabins or staying, and needed influences are exerted on objects therein. Accordingly, multiple technologies like vacuum, high pressure, ozone, catalysts, controlled atmosphere fresh-keeping, negative ions, disinfection and purification, humidification and dehumidification, air water production and low-temperature storage are regulated and integrated through the positive-negative pressure system and are combined and applied to the positive-negative pressure electric appliance, a breathing function is given to the electric appliance, and a positive-negative pressure electric appliance subdivision field is developed for upgrading and updating existing electric appliances and traditional technologies.