The invention provides a preparation method of a rose collagen peptide beverage with a function of maintaining beauty and keeping young. The product (namely the rose collagen peptide beverage) comprises the following components in parts by mass: 76-90 parts of multi-petal red rose extract, 4-8 parts of roselle extract, 0.5-4.5 parts of collagen peptide, 1-3 parts of concentrated fruit juice, 1-2 parts of rose cell liquid, 1-2 parts of resistant dextrin, 1-2 parts of L-arabinose, 0.6-1.2 parts of a stabilizer, 0.5-1.0 part of trehalose, 0.05-0.15 part of sodium citrate, 0.1-0.2 part of citric acid, 0.002-0.004 part of sucralose and 0.2-0.4 part of an antioxidant. The processing process comprises the following steps: extract preparation, proportioning, mixing, filtration, filling, sterilization and cooling. The beverage has a scientific formula and a simple preparation method. The prepared product not only contains collagen peptide, dietary fibers and a plurality of other nutrients, butalso has the characteristics of being tasty with slight sweetness and sourness, strong in rose fragrance, attractive in color and luster, high in stability and long in shelf life, and is a low-sugar and low-calorie healthy beverage for maintaining beauty and keeping young.