The design principles and instrument characteristics of capsule endoscopy indicate that it is best suited for the small intestine. Diseases of the small intestine that are suitable for capsule endoscopy include: unexplained gastrointestinal bleeding, upper and lower gastrointestinal endoscopy without positive findings, unexplained abdominal pain and diarrhea, inflammatory bowel disease (e.g., Crohn’s disease), small intestinal tumors, polyps, vascular malformations, unexplained iron deficiency anemia, intestinal malnutrition and malabsorption disease, and small intestinal imaging abnormalities. Capsule endoscopy can also be used to understand segmental enterocolitis, to observe the condition of surgical anastomoses, the development of small bowel polyp syndrome and the efficacy of certain small bowel diseases. In addition, capsule endoscopy can also be done for normal physical examination, and its clinical significance is that it can detect subclinical diseases and improve the early diagnosis and early treatment of small bowel diseases.