HLA-B27 positivity does not necessarily mean ankylosing spondylitis; it is also found in 10% of the normal population. HLA-B27 is one of the human leukocyte antigens. The positive rate of HLA-B27 in ankylosing spondylitis is about 90%, and it can also be seen in reactive arthritis, psoriatic arthritis and so on, and there is also a 10% positive rate in the normal population. Therefore, HLA-B27 positivity can only provide diagnostic clues for clinicians to diagnose ankylosing spondylitis. The diagnosis of ankylosing spondylitis requires a professional physician to analyze the patient’s condition, medical history, symptoms, and auxiliary examinations and gradually exclude other possible diseases before a definitive diagnosis can be made, in which the X-ray examination can provide an important basis for the diagnosis of sacroiliac joints if lesions are found. The test report should be interpreted by a professional physician, and it is recommended that patients with positive HLA-B27 test results should consult with the rheumatology department of a regular hospital.