Drug-coated balloon (DCB) is a medical device that wraps drugs that inhibit proliferation on the outer surface of the balloon to transfer drugs to the lesion site, and has been widely used in clinical treatment of vascular stenosis lesions, stent restenosis, etc., and has achieved good results. Inflation time is a very important factor in the clinical use of drug-coated balloons. The article quantitatively analyzed the relationship between the inflation time of DCB after implantation and the drug-transfer to the vessel to provide guidance for the development and clinical application of DCB. DCBs were used for in vitro animal vascular test to measure the drug content in blood vessel under the different inflation times, and the relationship between the drug-transfer to the vessel and the inflation time was analyzed. The results indicated an almost linear increase of drug-transfer to the vessel with the increase of the inflation time but less than 120s. When the inflation time exceeded 120s, drug-transfer to the vessel was basically maintained at about 15%, no longer raised significantly. The following conclusions are drawn that the relationship between the drug-transfer to the vessel and inflation time is nonlinear, and the optimal inflation time of DCB in the treatment of vascular stenosis should be determined by in vitro testing in order to improve the treatment outcomes.