The invention discloses a pomegranate-intestine-astringing vacuum-concentration blueberry fruit juice and a preparing method thereof. The pomegranate-intestine-astringing vacuum-concentration blueberry fruit juice is prepared from, by weight, 3-4 parts of dried sweet potato slices, 6-7 parts of pomegranate juice, 2-3 parts of cooked egg yolk, 1-2 parts of lily, 1-2 parts of fructus psoraleae, 300-310 parts of blueberries, 35-40 parts of syrup, 20-25 parts of citric acid, 1-2 parts of vitamins D, a proper amount of pectinase, a proper amount of ascorbic acid, a proper amount of xanthan gum, a proper amount of sodium alginate, a proper amount of beta-cyclodextrin and a proper amount of water. According to the omegranate-intestine-astringing vacuum-concentration blueberry fruit juice and the preparing method thereof, the dried sweet potato slices are put into the pomegranate juice and boiled for 1 hour, the pomegranate juice is immerged into the dried sweet potato slices, the taste is improved, and as the egg yolk is added, the nutrition is greatly improved.