AS is short for ankylosing spondylitis. Ankylosing spondylitis is an immune disease. Usually sacroiliac joint lesions appear first, such as lumbosacral pain or lumbosacral pain. The nature of pain is mainly resting pain, such as obvious lumbosacral pain after getting up in the morning or sedentary. After getting up, the symptoms can be alleviated, and the vertebral body movement is limited, such as obvious pain and rotation in the waist. With the progress of the disease, the pain in the lumbosacral region will gradually increase, and the lumbar rigidity will gradually appear. At this time, the imaging examination of sacroiliac joint will find joint space stenosis, bone destruction or joint fusion. In the later stage of the disease, the vertebral body will be completely stiff, which seriously affects the daily life of patients. In addition to joint manifestations, some patients may also have eye diseases, such as iritis, which should be treated as soon as possible.