The normal value of γ-glutamyl transpeptidase in the liver function test is 11-50 U/L, within this range, the patient’s γ-glutamyl transpeptidase is considered normal. γ-glutamyl transpeptidase is generally abbreviated as GGT, if the patient’s γ-glutamyl transpeptidase is elevated, it is also necessary to see whether other tests in the liver function are elevated. If the patient has elevated total bilirubin and direct bilirubin in combination with elevated alkaline phosphatase, then it is most likely that the GGT is elevated due to biliary obstruction. In this case, further ultrasound of the upper abdomen and MRI of the upper abdomen are needed to determine the cause of biliary obstruction, the most common cause being biliary stones. The most common cause is biliary stones. In this case, ERCP bile duct stone removal or surgical bile duct exploration and lithotripsy should be actively performed. If the obstruction is caused by tumor disease of the bile duct, then for middle and upper bile duct cancer, local resection of the tumor and biliary-intestinal anastomosis or hepatic-intestinal anastomosis should be actively considered. In addition, for tumors of the lower bile duct and tumors of the head of the pancreas that compress the bile duct, pancreaticoduodenectomy should be actively considered.