The difference between shoulder dislocation and acromioclavicular dislocation includes the following aspects: 1. The difference in the mechanism of injury, acromioclavicular dislocation is caused by acute external and violent injury to the shoulder joint. Part of shoulder dislocation is caused by acute external violent injury; the other part is due to habitual dislocation after shoulder injury; 2. The onset site is different. Shoulder lock joint dislocation occurs at the shoulder lock joint and can be divided into three levels, i.e. grade I, grade II and grade III. Grade III dislocation requires surgery, while grade I and grade II dislocation can often be treated conservatively. The onset of shoulder dislocation is at the shoulder joint, which can be divided into anterior dislocation and posterior dislocation; 3. The symptoms are different. Shoulder lock joint dislocation can often lead to local pressure pain as well as the piano key sign and limited shoulder joint movement. Most patients with shoulder dislocation can be treated conservatively, while most patients with shoulder dislocation need to be repositioned manually or by incision.