Patients often present with lumbosacral pain, mostly chronic, intermittent soreness and vague pain, which may spread to one or both buttocks and the back of the thighs, aggravated by the increase in the number of pregnancies or deliveries, but does not radiate in the direction of the sciatic nerve, aggravated by walking, standing, weight bearing and exertion, and the pain cannot be significantly aggravated by coughing and sneezing, and the symptoms are relieved after rest. The patient’s lumbosacral angle increased, with localized pressure pain and muscle tension, positive pelvic separation and squeeze test, and positive “4” test. On X-ray examination, the sacroiliac joint gap is neat and clear, and the bone density of the iliac olecranon near the sacroiliac joint surface is increased, showing a dense zone of bone with uniformly dense white edges and clear edges, and the bone trabeculae disappear without bone destruction. This disease should be distinguished from early ankylosing spondylitis and sacroiliac joint tuberculosis. To prevent iliac dense osteoarthritis, multiple pregnancies should be avoided and rest should be observed after delivery. In particular, young mothers should avoid prolonged hugging of children, bending over to do housework, etc. The treatment of this disease can be used drugs, closure, physiotherapy, acupuncture, massage, etc. When symptoms are obvious, it is advisable to rest on your back in a hard bed for 1-3 weeks, and when symptoms are reduced and leave the bed, you should bring a waist brace for protection and gradually increase the amount of activity.