Abstract: The dynamic balance of intestinal flora is an important sign of maintainance of human health. Environment is an important factor affecting the diversity and abundance of intestinal flora. Intestinal flora can adapt to environmental changes by changing its composition. People who have lived in low-oxygen environments for generations have certain genetic changes that also affect the diversity and abundance of gut flora. The study on the correlation between hypoxic environment and intestinal flora is of great significance to the health of people in hypoxic environment. At present, the specific mechanism of the effect of hypoxic environment on intestinal flora composition has not been reported. In this paper, the changes of human intestinal flora and the possible causes in low oxygen environment at high altitude are reviewed, in order to provide reference for subsequent research.