The invention relates to a hydrolyzed sericin peptide preparation method, and belongs to the technical field of protein separation and purification. According to the present invention, tasar silkwormcocoon shell or waste mulberry silk is used as a raw material, the tasar silkworm cocoon shell is washed, a sericin solution is prepared, a hydrolyzed sericin peptide solution is prepared, an activated macroporous resin decolorization system is assembled, a hydrolyzed sericin peptide decolorization solution is prepared, an activated MCI GEL resin system is assembled, a hydrolyzed sericin peptide grading separation solution is prepared, a hydrolyzed sericin peptide grading separation concentration solution is prepared, a hydrolyzed sericin peptide grading separation ethanol removing concentration solution is prepared, and hydrolyzed sericin peptide freeze-drying powder is prepared so as to obtain the product; by using multi-enzyme combined hydrolysis, ultra-filtration, nano-filtration separation, macroporous resin decolorization, MCI GEL resin grading separation, low-temperature concentration, freeze drying, and other modern chemical industry technologies and equipment, such that the preparation method has characteristics of convenient operation, mild condition, high efficiency, energy saving, low production cost and the like; and the product prepared by using the preparation methodcan be widely used in the fields of nutritious daily chemicals, fiber modification, and the like.