Due to an aging population，the incidence of osteoporotic fractures is increasingly rapidly in China，and the demand for bone repair and regeneration is also growing rapidly. Osteoporosis，diabetes，inflamma⁃ tion and tumors，trauma，congenital skeletal malformations are directly or indirectly lead to bone defect，and greatly influence the life quality of patients. The treatment of bone defect is always a difficult point in clinic. Metformin has been widely used in type 2 diabetes mellitus（T2DM）. Recently，a large number of studies have shown that metfor⁃ min also plays an important role in repairing different types of bone defects. The application status and clinical trails of metformin in bone defect repair were emphatically reviewed in this article，as well as prospected the development.