The invention discloses milk suitable to be drunk by pregnant women and lactating mothers and a preparation method thereof. The milk is added with long-chain unsaturated fatty acid and nutrients, and the nutrients comprise folic acid, vitamin A, vitamin D, vitamin E, vitamin C, Fe, Ca and Zn, wherein each 100ml of the milk contains 100 to 10,000mu g of long-chain unsaturated fatty acid, 60 to 120mu g of folic acid, 180 to 360IU of vitamin A, 80 to 160IU of vitamin D, 10 to 20mg of vitamin E, 50 to 100mg of vitamin C, 1.0 to 2.0mg of Fe, 140 to 300mg of Ca, and 0.5 to 1.0mg of Zn. The liquid milk which is prepared by adopting a sterile postaddition technology and is rich in the long-chain unsaturated fatty acid, the folic acid, immunoglobulin, and various vitamins and mineral substances has good taste and high nutrient value, can promote bones of babies to be strong, strengthen the growth of brains and eyesight, improve the immunological competence, and is particularly suitable to be drunk by the pregnant women and the lactating mothers.