The common causes of sacroiliac joint pain include sacroiliac arthritis, sacroiliac joint dislocation or fracture, ankylosing spondylitis and so on. 1. Sacroiliac arthritis is caused by low activity of articular chondrocytes, weakening of hip muscles and other factors that cause soft tissue injury, triggering aseptic inflammation causing pain, mostly occurring in older obese patients. 2. Sacroiliac joint dislocation or fracture, due to trauma, chronic strain injury caused by sacroiliac joint fracture or dislocation, or severe osteoporosis patients, even if there is no obvious history of trauma, sacroiliac joint fracture may occur, thus causing pain. 3. Although ankylosing spondylitis mainly invades the spine, it can also involve the sacroiliac joints and the surrounding joints. Involvement of the sacroiliac joints can lead to sacroiliac arthritis and pain. Causes of sacroiliac joint pain are more reasons, may also be related to bone tumors, local soft tissue injuries and other diseases, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, to clarify the cause of the disease, targeted treatment.