The small intestine can have cancer. In addition to tumors of epithelial origin, the small intestine may also suffer from tumors of non-epithelial origin, including mesenchymal tumors, hemangiomas, lymphomas, lipomas, neuroendocrine tumors, smooth muscle tumors, and so on. Small intestinal tumors can be benign or malignant, and are usually associated with different degrees of gastrointestinal bleeding and small intestinal obstruction, as well as abdominal pain, bloating, diarrhea, fever and other symptoms. The diagnosis of small intestine cancer is relatively difficult, especially the early diagnosis, which is related to the special anatomical location of small intestine. The small intestine belongs to the middle gastrointestinal tract, and the upper and lower gastrointestinal tracts are usually given priority in diagnosis, so the middle gastrointestinal tract is the next scope of examination to be considered. The most common tumor of the small intestine is mesenchymal tumor, which has different degrees of malignant potential. When there are clinical symptoms in the gastrointestinal tract and no abnormalities are found after gastroscopy and colonoscopy, small intestinal disease can be considered. At this time, further definite diagnosis can be made by capsule endoscopy, small intestine microscopy and small intestine CT examination methods.