Elbow dislocation accounts for half of the total dislocation of the four major joints in the body. The lower end of the humerus that constitutes the elbow joint is wide and thick inside and outside, and thin and flat in front and back. The side is protected by strong ligaments, and the front and back of the joint capsule are quite weak. The movement of the elbow joint is mainly flexion and extension. The coronoid process of the ulna is smaller than the olecranon process. Therefore, the ability to resist the backward movement of the ulna is weaker than the ability to resist the forward movement. Therefore, posterior dislocation of the humeral joint is much more common than dislocation in other directions. Fresh dislocation will not leave obvious functional impairment after early correct diagnosis and appropriate treatment. If it is not treated promptly and correctly in the early stage, it may lead to serious functional impairment in the late stage. At this time, no matter what kind of careful treatment is given, it is difficult to restore normal function, but only to obtain varying degrees of functional improvement. It often occurs in adolescents, and it also occurs in adults and children from time to time. Because the types of elbow dislocation are more complicated and often combined with other structural injuries of the elbow, attention should be paid during diagnosis and treatment to prevent misdiagnosis.