As a classic nitrogen-containing bisphosphonate drug, alendronate (ALN ) is very effective in preventing diseases caused by bone loss, mainly by down-regulating osteoclast activity and inhibiting bone resorption, thereby promoting osteogenesis. In the oral bone-resorption diseases, the destruction of the balance between osteoblast-promoting bone formation and osteoclast-mediated bone resorption in the body is considered to be the only possible reason. Although ALN has advantages in the application of oral bone-resorption diseases, long-term intravenous or oral application of ALN can lead to side effects such as bisphosphonate-related osteonecrosis of the jaw(BRONJ), renal failure and esophageal damage. Whether ALN can be safely and effectively applied to oral bone-resorption diseases by changing the route of administration to reduce its adverse reactions is a difficult problem that needs to be solved in the short term. Therefore, this paper briefly expounds the mechanism of ALN on bone metabolism, and discusses the advantages and disadvantages of its application in the oral bone-resorption diseases, to provide theoretical guidance for the application of ALN as a local drug to treat oral bone-resorption disease