The small intestine is the longest organ in the digestive tract, and the clinical diagnosis of small intestinal diseases is very difficult due to many factors such as insidious clinical onset, lack of symptom specificity, and deep lesion sites. People try to insert the endoscope into the whole small intestine by various methods, including the advancement method, probe method, cable method, etc., but the results are disappointing, and up to 50% of the small intestine diseases cannot be diagnosed, the diagnosis and treatment of the whole small intestine diseases is always a gap in the field of endoscopic medicine, and it is the last blind spot in the diagnosis and treatment of digestive tract diseases. Various conventional small bowel disease examination methods, including ordinary propelled small enteroscopy, barium meal of the whole digestive tract, barium irrigation of the small bowel, angiography, isotope scanning and so on, have their limitations and are unable to meet the needs of clinical diagnosis. The introduction of capsule endoscopy in 2001 provided a brand new means of examination for the diagnosis of small intestinal diseases. Non-invasive, non-cross-infectious methods are easily accepted by patients, and its positive detection rate of small intestinal diseases was reported to be 76.6% by Gao Zhizheng et al. and 74.4% by Wen Xiaoheng et al., which is an improvement compared with the other traditional methods. However, the current capsule endoscopy can not be well localized, directed to the intestinal lumen can not be inflated, can not be biopsied, not to mention the treatment, and intestinal fluid affects the observation, image resolution is not as good as the electronic endoscopy, which affects the play of its clinical value. Capsule endoscopy may cause intestinal obstruction if it cannot be discharged from the body and must be removed surgically. Dual balloon electronic small enteroscopy in the area it can reach, most of the lesions can be found, our positive detection rate of 88.24%, with the highest positive rate of black stools and vomiting, the lesions found are small bowel crohn’s disease, small bowel tumors, small bowel vascular malformations, small bowel capillary dilatation, small bowel inflammation, ileal ulcers, small bowel diverticulum and hemorrhage, hookworm disease, jejunum lipoma, duodenal ulcers, small bowel torsion, small bowel ulcers, ileal ulcers and bleeding. ulcers, small bowel torsion, with small bowel crohn’s disease, small bowel vascular malformations and small bowel capillary dilatation sign being the most common. Gastroscopy and colonoscopy were necessary to rule out gastric and colonic disorders before performing dual-balloon electronic small bowel scintigraphy. There was another case of blood in stool of unknown etiology, first transanal double balloon electronic small enteroscopy only found a large amount of blood in the intestinal lumen, but did not find the site and cause of bleeding, and then transoral small enteroscopy found that there was a stromal tumor with active bleeding in the lower 20 cm of the flexor ligament. Special attention should be paid to the hookworm disease of the small intestine, mainly in the jejunum, but also in the duodenum and the middle and upper ileum, in order to avoid excessive examination, it is best to do the first stool to find hookworm eggs. The combination of upper and lower double balloon electronic small enteroscopy basically completes a thorough and blind-free examination of the entire digestive tract, and has the characteristics of clear image, biopsy, and controllable operation. Whether it is the diagnosis of etiology, or the scope and extent of lesions have greater advantages, to achieve the practicality of strong, good operational performance, the clinical value of the purpose of reliable, is one of the most effective methods of diagnosis of small intestinal diseases. Double balloon electronic small bowel microscope operation time is long, the inspection range is wide, although the tolerance of transanal intake is better, but the tolerance of transoral intake is obviously reduced, under anesthesia transoral intake, its tolerance is obviously improved, and better inspection effect can be achieved. Transoral access under anesthesia is a better choice, but in the process of access, pay attention to the observation of the patient’s response, especially respiration and heart rate and oxygen saturation, to avoid the occurrence of complications.