The HLA-B27 gene is a susceptibility gene for ankylosing spondylitis, but HLA-B27 negativity cannot rule out ankylosing spondylitis. Ankylosing spondylitis is a polygenic genetic disease triggered by a combination of genetic and environmental factors. HLA-B27 is the main susceptibility gene for ankylosing spondylitis, and more than 210 HLA-B27 subtypes have been identified. However, epidemiologic surveys show that only about 90% of ankylosing spondylitis patients are HLA-B27 positive, and 10% are still HLA-B27 negative. It is important to note that if long-term lower back pain, morning stiffness, limited lumbar spine movement and other symptoms, activities to improve the rest does not improve, even if the HLA-B27 is negative, we should be alert to the occurrence of ankylosing spondylitis. At this time, it is recommended to go to the hospital to improve the imaging examination, to clarify the cause of the disease to take standardized treatment, in order to control the symptoms and improve the quality of life. Patients are advised to go to the hospital in time to avoid delay.