Sacroiliac joint dense osteitis is an increase in bone density of the articular surface between the ilium and the sacrum, either unilaterally or bilaterally, because it is a self-limiting disease that usually disappears or resolves after six months to several years. However, the increased density does not disappear with it. The cause of the disease is still unknown and may be related to pregnancy, trauma, infection and strain. The main manifestations are as follows: 1. pain in the lumbosacral and lower back, occasionally lower buttock and posterior thigh radiating pain, pelvic separation test and four-letter test are often positive during physical examination, and patients often have increased blood sedimentation. 2. sacroiliac joint can also lead to radiating chronic pain in the lower limbs, but there is no bone destruction. Sacroiliac arthritis can be treated as follows, for the less severe cases, bed rest and external fixation of lumbar circumference can be appropriate, for the severe cases, oral celecoxib and loxoprofen sodium tablets are needed, while the patient should be encouraged to exercise the abdominal muscles. In severe cases, sacroiliac joint fusion surgery is required, and the prognosis is generally better for patients.