Abstract: With the acceleration of population aging, osteoporosis has become an important public health problem in China and even the world. Estrogen replacement therapy, teriparatide and some other drugs are commonly used in the prevention and treatment of osteoporosis, but they all shown some side effects. Even the most acceptable method, calcium and vitamin D supplementation, doesn't work well for some people, and overdose also increases the risk of stones and cardiovascular disease. Collagen is the most abundant protein in bone. A number of studies have shown that collagen hydrolysates can improve bone metabolism, and have the advantages of wide source, high bioavailability and no side effects, so collagen peptides are good food-borne ingredients for the prevention of osteoporosis. This review summarizes the in vivo and in vitro efficacy evaluation and mechanism of collagen peptides in promoting bone formation and slowing bone loss, hoping to provide a certain theoretical basis for the development of collagen peptide functional foods for preventing osteoporosis.