Method for extracting low molecular weight collagen from cattle bone

The invention belongs to the collagen hydrolysis field, and in particular to the method for extracting low molecular weight collagen from cattle bone. According to the invention, the cattle bone after being degreased is crushed and grinded to bone meal with particle size of 0.5-1000mum; the bone meal is dispersed in water to form bone slurry, a series postprocessing technology is employed to remove enzymatic hydrolysis and enzymes inactivating is carried out to obtain solid residues and soluble inorganic salt impurity in a protein liquid, thereby the low molecular weight collagen with high purity can be obtained. According to the invention, the low molecular weight collagen product with average molecular weight of 1000-5000g/mol can be obtained, the ash content is lower than 1.5%, and the obtained low molecular weight collagen can be used in food, medicine, and cosmetic and health product.