Japan's Ministry of Agriculture and Forestry Fruit Research Institute developed a new method of fruit preservation, that is, "cold temperature and high humidity storage method." It can greatly extend the fruit preservation time without adversely affecting the fruit. Its practice is: to adjust the temperature of the cold room to 0 to 1°C, adjust the humidity to 95%, and inject a mixture of negative ions and ozone. Its benefits are: some fruits can not withstand the low temperature, but high humidity can solve this problem; low concentrations of ozone can not be sterilized, but with the addition of negative ions after the sterilizing ability has been significantly improved, will not have adverse effects on the fruit. Compared with previous methods, the preservation time of peaches, grapes and pears can be extended by 5 times, and the citrus can still be eaten after being removed for 5 months.