Congenital dislocation of the hip (CDH), also known as DevelopmentalDysplasiaoftheHip (DDH), is relatively common in newborns and is a lesion that has a significant impact on children’s health and is one of the major disorders causing physical disability in children. Its incidence varies more markedly in different regions of the world, with a significantly higher incidence in ethnic groups who prefer to use strapping methods that fix the hip in the extended, inward position in newborns. It is also found to be more prevalent in infants born by cesarean section who are heavier. However, the incidence is not always in children, and some cases with early, less severe effects and hip pain as the hip degenerates can be found in older patients. There may be a combination of osteoarthritic manifestations of the hip joint. The subtype of congenital hip dislocation: 1, simple congenital hip dislocation (1) hip dysplasia: also known as hip instability, X-ray films are often characterized by an increase in the acetabular index, most of them use the external booth of the hip joint and subsequently heal themselves, about 1/10 will develop into congenital hip dislocation, and a few cases persist with acetabular dysplasia and develop symptoms when they grow older. (2) Hip subluxation: X-ray has an increased acetabular index with the acetabulum covering part of the femoral head, which is an independent type that can persist for a long time without transforming into total dislocation. (3) Total dislocation of hip: the femoral head is completely dislocated from the acetabulum, which can be divided into four degrees according to the level of dislocation of the femoral head: Ⅰ degree: the femoral head is only displaced outward and located at the same level of the acetabulum. Ⅱ degree: the femoral head is displaced outward and upward, equal to the level of the outer upper part of the acetabulum. Ⅲ The prolapsed femoral head is located at the site of the iliac wing. Ⅳ prolapsed femoral head displaced upward to the level of sacroiliac joint. 2.Deformed congenital hip dislocation Typically, both hips are dislocated, both knees are stiff in the straight position and cannot be flexed, both feet are flat-footed in the external rotation position, and the upper limbs are often combined with deformities. Signs: In unilateral dislocation during allis sign dislocation, the affected limb is shortened, both knees are flexed to 90° when lying down, the top of both knees are not in one plane, the lower side indicates dislocation. trendelenburs test makes the child stand on one foot, the opposite pelvis cannot be lifted to maintain body balance, then the standing side of the hip has lesions. Treatment: In the early stage, if the pain is mild, the activity can be reduced and the pain can be treated symptomatically. For patients with heavier impact on life, joint replacement treatment can be considered.