Objective To explore the clinical application value of transparent cap gastroscope in the Billroth Ⅱ procedure after subtotal gastrectomy in patients with bile duct diseases by endoscopic retrograde cholangiopancreatography(ERCP).Methods 20 patients underwent ERCP with Billroth Ⅱ gastrectomy postoperation with biliary diseases were selected as the research subjects,selected the transparent cap gastroscope ERCP,successful intubation received endoscopic sphincterotomy(EST) and(or) endoscopic nasobiliary drainage(ENBD),endoscopic papillary balloon dilatation(EPBD),endoscopic biliary metal stent drainage(EMBE),endoscopic biliary drainage(ERBD) treatment.Results 20 patients with Billroth Ⅱ gastrectomy after angiography were successful,the successful rate was 100.00%,14 cases of EST patients,4 patients underwent EPBD surgery,common bile duct stones all took the net,took the net rate of 100.00%;1 case of bile duct cancer underwent EMRE resection,1 case of bile duct stenosis after biliary tract surgery ERBD operation,hyperamylasemia occurred in 1 case,no serious complications such as bleeding and perforation of digestive tract.Conclusion Billroth Ⅱ gastrectomy postoperative patients with bile duct disease receiving ERCP,endoscopic transparent cap can provide good operative field for jejunal loop inside the mirror,improve the success rate of bile duct intubation,conducive to the removal of stones,improve the success rate of surgery,reduce complications security,safety of operation,and can be used in clinical application.