The whole process of ultrasound endoscopy usually includes preparation, endoscope insertion, and scanning examination. Ultrasound endoscopy is a technology that combines ultrasound and endoscopy. While endoscopic direct observation of gastrointestinal mucosal lesions, endoscopic ultrasound can be utilized for real-time scanning, which can obtain the histological characteristics of the hierarchical structure of the gastrointestinal tract and the ultrasound images of the surrounding neighboring organs, thus further improving the diagnostic level of endoscopy and ultrasound. The preparation of ultrasound endoscopy includes understanding the basic condition of the patient, performing various laboratory tests, etc., and the patient should fast for 4-6 hours before the examination, and the patient should be helped to take the left lateral position during the examination, after which the ultrasound endoscope is inserted into the gastrointestinal tract through the mouth to carry out the scanning examination. Because ultrasonic endoscopy is less traumatic, generally will not occur serious complications, so after the examination generally do not need special treatment, fasting and water can be 2 hours. Ultrasound endoscopy should be performed under the guidance of a specialized doctor.