Biodegradable magnesium (Mg)-based metals can undergo spontaneous corrosion and full degradation in the human body, releasing magnesium ions, hydroxides, and hydrogen. Mg and its alloys have shown preliminary success as an implantable biomaterial. Current research on biodegradable Mg-based metals addresses clinical challenges, including material design and preparation, property enhancement, and exploring relevant biological functions. This review provides a comprehensive overview of the biomedical applications of Mg-based implants across eight fields: cardiovascular, orthopedics, stomatology, general surgery, neurosurgery, fat metabolism, and other potential areas, building upon previously published work. The challenges and prospects of biodegradable Mg-based implants in these application fields are discussed.