Abstract: Provided is use of a SMO inhibitor in the preparation of a drug for preventing, delaying or alleviating access stenosis of arteriovenous fistula. It is creatively found herein that a SMO inhibitor can protect endothelial cells under the stimulation of high glucose and alleviate endothelial cell dysfunction, and specifically reduce lactate dehydrogenase (LDH), reduce apoptosis and reduce the production of inflammatory cytokines TNF-?, MCP-1, and IL-6. Furthermore, it is found herein that the SMO inhibitor can improve endothelial cell dysfunction by increasing the blood flow velocity in blood vessels, increasing the inner diameter of the blood vessel, improving the vascular intima thickening and reducing the production of inflammatory cytokines, thereby achieving the purpose of preventing, delaying or alleviating the access stenosis of arteriovenous fistula.