The duodenum is located in the upper abdomen, starting proximally at the pylorus and distally at the suspensory ligament of the duodenum, which is located in a C-shape in the upper abdomen. The duodenum is the portion of the small intestine that begins in the upper abdomen, the upper end connects to the pylorus of the stomach, the lower end to the jejunum, and is anchored to the posterior abdominal wall by the duodenal suspensory ligament, with the entire duodenum encircling the head of the pancreas. The typical anatomical landmark of the duodenum is the duodenal suspensory ligament, also called the flexor ligament, which is mainly subjected to blood supply from the superior pancreaticoduodenal artery, and the inferior pancreaticoduodenal artery. The duodenum projects on the surface of the body approximately above the umbilicus, and pain in this area needs to be considered as a duodenal ulcer, etc. It can be diagnosed by gastroscopy, barium x-ray, etc. When duodenal disease is considered, it is important to go to the hospital in a timely manner, and the diagnosis is confirmed by examination and timely treatment.