Abstract: The rice protein peptide powder was obtained by the pretreatment of rice dreg for removing saccharides and lipids, and then by the enzymolysis and decolorization to the rice residue protein followed by spray drying.Using the contents of dissolubility protein and oligopeptide as indicators, an orthogonal experimental method was adopted to optimize the enzymolysis technology.The optimum conditions were attained:the ratio of trypsin and protamex 3:2, the proportion of enzymolysis solid to liquid 1:9, temperature 50℃, pH8.0 and time 3.0h.The contents of dissolubility protein and oligopeptide were 23.49% and 16.35% respectively, compared with 4.35% and 0.97% which weren't treated with enzyme.And the product of rice residue protein peptide was characterized including infrared spectrometry, size distribution and scanning electron microscope, which proved the rice residue protein peptide made by method purity was high.