The invention discloses a formula of a collagen beverage. A main material of the formula omprises collagen peptide, blackberry concentrated juice, galactooligosaccharide, blueberry concentrated juice,isomaltooligosaccharide, elastin peptide, gamma-aminobutyric acid, chitosan oligosaccharide, a yeast extract, edible bird nest powder, acerola cherry concentrated powder and broccoli powder; and an auxiliary material is purified water. The invention discloses a preparation method of the collagen beverage. The preparation method comprises four steps; collagen peptide, blackberry concentrated juice, galactooligosaccharide, blueberry concentrated juice, isomaltooligosacharide, elastin peptide, gamma-aminobutyric acid, chitosan oligosaccharide, the yeast extract, edible bird nest powder, acerolacherry concentrated powder and broccoli powder are used as main materials, a liquid finished product is prepared through a simple mature process, so that the variety of collagen products is increased,it is convenient for people to take, effectively absorbs collagen, achieve the beautifying effect, promote sleep, provide more nutritional ingredients for people, and achieve the effects of preventing and treating diseases and building bodies, thereby the collagen beverage is more beneficial to the health of bodies.