Milk is made from fresh milk by pasteurization. It is characterized by sterilization at a low temperature of about 72-85℃, killing harmful flora in milk and retaining nutrients and pure taste. After centrifugal cleaning, standardization, homogenization, sterilization and cooling, it is filled in liquid state and directly supplied to consumers for drinking. Because pasteurized milk contains a certain amount of bacteria and yeast, its transportation, storage and sales temperature should be controlled at 2℃~ 6℃. Under pasteurization conditions, especially under high temperature and rapid pasteurization conditions, the influence on milk flavor and vitamins is relatively small.