SKIN MAP packaging, also known as vacuum packaging, is carried out according to the principle of atmospheric pressure. The main function of vacuum bag is to deoxygenate, which is conducive to preventing mildew and deterioration. Vacuum packaging is to remove the oxygen in the packaging bag and food cells with the pump, so that microorganisms lose the "living environment", inhibit the reproduction of bacteria and other microorganisms, to avoid oxidation, mildew, at the same time for some soft items, after the automatic vacuum packaging machine packaging, can reduce the packaging volume, convenient transportation and storage. The freshness period of vacuum packaging is longer than that of air conditioning. Generally, vacuum packaging is more than 1 month, which emphasizes the preservation time.