Mucinous adenocarcinoma of common bile duct belongs to malignant tumor of bile duct epithelium, which is rare in clinic and is mainly treated by surgery, but the prognosis is not satisfactory after surgery. Mucinous adenocarcinoma of common bile duct is a kind of bile duct epithelial malignant tumor occurring in the common hepatic duct, which is a rare type of cholangiocarcinoma. It can occur in the intrahepatic bile duct, and the mucus secreted by the tumor can cause obstruction of the common hepatic duct, which is easy to be directly infiltrated or metastasized by lymphatic metastasis, therefore, the prognosis of the tumor is unsatisfactory. The treatment of mucinous adenocarcinoma of the common bile duct is based on surgery, which adopts radical resection and partial hepatectomy if necessary. If the primary focus is completely removed, the prognosis is relatively good; if the tumor is metastatic, the prognosis is poor, so the treatment is difficult. It is recommended to go to regular hospitals for consultation and treatment, and follow the doctor’s instructions to avoid delaying the condition.