Intestinal methanogens are anaerobic bacteria that produce methane from hydrogen and carbon dioxide, studies have confirmed that they are closely related to human intestinal diseases, therefore, it is of great significance to explore the mechanism of intestinal methanogens in intestinal diseases. This paper reviews the characteristics, types and colonization characteristics of intestinal methanogens as well as their relationship with obesity, irritable bowel syndrome, inflammatory bowel disease, colorectal cancer, diverticulosis and other diseases, focusing on the possible mechanism of intestinal methanogens in these diseases, so as to provide new ideas for the prevention, diagnosis and treatment of human intestinal diseases.