The treatment of extrahepatic bile duct dilatation should be decided according to the cause of the disease. If it is caused by tumor, radical tumor treatment and radiotherapy should be performed according to the condition of the disease; if it is congenital, bile duct reconstruction should be performed; and if it is caused by stones, choledochotomy should be performed to remove the stones. 1. Extrahepatic bile duct dilatation due to tumor: it is common in cholangiocarcinoma, especially in lower cholangiocarcinoma, at this time, according to the staging of the tumor to assess whether it can be treated surgically; if it can be treated surgically, radical resection of cholangiocarcinoma can be carried out and then assisted with radiotherapy; if the clinical staging of cholangiocarcinoma is later and combined with the cure, it is feasible to carry out internal bile-intestinal drainage or cholangiocarcinoma stent, etc. and then assisted with radiotherapy, and the drugs include fluorouracil, cisplatin and so on. 2. Congenital bile duct dilatation: mostly caused by bile duct malformation, common treatment for bile duct dilatation part of the bile duct resection bile duct reconstruction. 3. Choledochal stone: obstruction caused by stone can lead to bile duct dilatation, in this case, it is feasible to laparoscopic choledochotomy to remove the stone + T-tube drainage, if the stone is small, it can be carried out through the endoscopic retrograde cholangiopancreatography (ERCP) for stone removal. If there is dilatation of the extrahepatic bile ducts, it is recommended to go to the hospital in time and follow the doctor’s instructions.