The cause and pathogenesis of ankylosing spondylitis is unclear, and most scholars believe that its occurrence is related to genetics, infection, immune dysfunction, endocrine disorders, and other factors. The first gene associated with the onset of AS was HLA-B27, which has been shown to be directly involved in the onset of AS and is the primary associated component of AS. With the advancement of genetic research and scientific techniques, a large number of genes other than HLA-B27 have been proposed to be associated with the development of AS. 2, Immune factors: autoimmune hypofunction is associated with AS, and AS patients have a large number of inflammatory T cells and monocytes-macrophages infiltrating the bone, joint and synovial tissues, and there is an immune response. 3. Infectious factors: The main ones that have been proposed as possibly related to the development of AS are Klebsiella pneumoniae, Salmonella and other intestinal parasitic G-bacteria and Chlamydia that cause upper respiratory tract infections and intestinal infections. Trauma, parathyroid disease, endocrine and metabolic defects have been reported to be associated with the development of AS. And environmental factors such as wind, humidity and cold are also causative factors of the disease. Investigation of special populations found that fixed work postures and stereotypical local training can trigger AS.