Ultrasound endoscopy is a technique that combines ultrasound and endoscopy to examine the structure and function of the digestive tract. Ultrasound endoscopy is less invasive, has a lower possibility of complications, and in combination with Doppler technology, can also view blood flow. The specific operation process is as follows: 1. Pre-operative preparation: The doctor should understand the basic situation of the patient in advance and explain to the patient in time the purpose and necessity of the examination, as well as the related precautions. Before the ultrasound endoscopy, various laboratory tests should be done, including routine blood and urine tests, liver function tests, and coagulation function tests. Patients should fast for about 4-6 hours before the ultrasound endoscopy, and if necessary, a bowel cleanse should be performed. About 20 minutes before the examination, oral defoamer and intramuscular injection of scopolamine should be given, and whether sedatives, anesthetics, and other drugs should be injected should be chosen according to the patient’s individual condition; 2. Operation procedure: Upper gastrointestinal examination is generally performed in the left lateral position with upper and lower limbs flexed and head slightly tilted back. The ultrasound endoscope is inserted into the gastrointestinal tract through the mouth, and the direct contact method and water bladder method can be selected according to the patient’s condition to scan the organs of the gastrointestinal tract and adjacent tissues; 3. Postoperative treatment: ultrasound endoscopy is relatively safe and no serious complications generally occur. No special treatment is generally required after the examination, and fasting and water fasting for 2 hours is sufficient. Ultrasound endoscopy can generally determine the origin, nature and severity of gastrointestinal tumors, and is more sensitive for diagnosing chronic pancreatitis, and can also diagnose the extent of mediastinum and varicose veins lesions.