This disease is a serious injury. Because the structure of the hip joint is stable, strong external force is required to cause dislocation. Soft tissue damage is also serious at the same time as dislocation. And it is often combined with other parts or multiple injuries. Therefore, most patients are young and middle-aged people with strong activities. It is generally divided into three types: anterior, posterior and central dislocation. After dislocation, the femoral head is located in front of the Nelaton line (the line connecting the anterior superior iliac spine and the ischial tuberosity). It is an anterior dislocation. The dislocation behind this line is a posterior dislocation. The femoral head is squeezed to the midline, breaks through the acetabulum and enters the pelvis, which is a central dislocation. Among the three types, posterior dislocation is the most common. This injury should be treated as an emergency, and the earlier the reduction, the better the effect.