The methods to exclude cancer in inflammatory stricture of common bile duct include ultrasonography, MRCP, ERCP, intraoperative cholangioscopy, ultrasonic endoscopy and so on. 1. Ultrasonography: Ultrasonography is the most commonly used test for initial screening of bile duct diseases, which can observe whether there is any dilatation or swelling in the bile duct and then determine the bile duct diseases, but sometimes it is difficult to identify inflammatory stenosis or malignant tumor of the bile duct, and further examination is needed. 2.MRCP: MRCP is known as magnetic resonance cholangiography, which utilizes the water component of bile in the bile ducts for imaging, and can observe the morphological changes of the whole bile ducts and show the parts of bile ducts that are narrowed, obstructed, or occupied to identify inflammatory stenosis and malignant lesions. 3.ERCP: ERCP is known as endoscopic retrograde cholangiography, which is performed through duodenoscopy by injecting contrast agent into the common bile duct through the duodenal papilla for imaging, and it can clearly show the morphological changes of the whole bile duct. 4. Intraoperative cholangioscopy: Intraoperative cholangioscopy is a kind of inspection means to cut the common bile duct and put in the cholangioscopy to observe the situation in the bile duct during bile duct surgery, which is able to observe the lesions in the bile duct under direct vision. 5. Ultrasound endoscopy: ultrasound endoscopy is a new examination method combining endoscopic instruments with miniature ultrasound probes, which is able to determine the scope and nature of biliary tract diseases through ultrasound scanning, and is also able to carry out puncture biopsy under ultrasound guidance to further clarify the diagnosis. Patients suffering from bile duct stenosis and suspected of cancer are recommended to go to the hospital as soon as possible to consult a professional doctor to take appropriate examination means and make a clear diagnosis as soon as possible.