To evaluate the value of endoscopic retrograde cholangiopancreatography（ERCP）and SpyGlass in the diagnosis of intraductal papillary mucinous neoplasm of the bile duct (IPMN-B). Data of patients who underwent ERCP and SpyGlass in Hangzhou First People's Hospital from January 2016 to December 2019 were analyzed. ERCP and SpyGlass features, complications, clinicopathologic characteristics and prognosis were retrospectively analyzed.A total of 9 patients (5 benign lesions and 4 malignant lesions) were included.ERCP was successfully performed in 9 cases, while SpyGlass was technically successful in 8 cases. Endoscopy showed mucus outflow from the papilla in 5 cases, and the mucus was removed by the balloon of ERCP in 8 cases.ERCP showed bile duct diffuse dilatation and filling defects in all patients. SpyGlass found the mucus in the bile duct in all patients. SpyGlass showed lesion mucosa were fish-egg like without vascular images (Ⅱtype, 3 cases), fish-egg like with vascular images (Ⅲ type, 1 case), villous (Ⅳtype, 4 cases). SpyGlass defined extent of the lesion in 8 cases. SpyGlass found that the lesion involved the intra and extrahepatic bile ducts in one case. Therefore, liver transplantation was recommended to avoid surgical exploration. One type Ⅲ lesion underwent a direct biopsy. The pathology showed moderate dysplasia, which was consistent with the postoperative pathology. No complication occurred. ERCP combined with SpyGlass could clarify the scope of IPMN-B and provide basis for surgical options, which is safe and effective in IPMN-B diagnosis.