Developmental dislocation of the hip, also known as congenital dislocation of the hip (CDH), is a lesion that has a significant impact on the health of children, and the clinical outcome is satisfactory if early diagnosis and treatment are achieved. Developmental hip dislocation, also known as congenital hip dislocation, is one of the major disorders that cause physical disability in children. Fractionation of developmental hip 1, simple congenital hip dislocation (1) hip dysplasia: also known as hip instability, X-ray films are often characterized by an increase in acetabular index, most of them use external hip booth and subsequently heal themselves, about 1/10 will develop into hip dislocation in the future, and a few cases persist with acetabular dysplasia and develop symptoms when they grow older. (2) Hip subluxation: X-rays show an increase in the 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 joint: the femoral head is completely dislocated from the acetabulum, which can be divided into four degrees according to the height of the 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, which is equivalent to the level of the outer upper part of the acetabulum; Ⅲ degree: the dislocated femoral head is located at the part of the iliac wing; Ⅳ degree: the dislocated femoral head is displaced upward to the level of the sacroiliac joint. 2.Fetal 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. Treatment strategy according to age is divided into 5 treatment groups: neonatal group 0-6 months; infant group 6-18 months; toddler group 18-36 months; child group 3-8 years; adolescent group 8-10 years. Neonatal group 0-6 months: Pavlik dressing is usually considered a safe and effective first-line treatment. Harding et al. reported that treatment with Pavlik dressing started between birth and 21 days was three times more successful than treatment with Pavlik dressing started after 21 days of life. In children with positive Ortolani and Barlow tests, the success rate of treatment with the Pavlik dressing device was 85-95%. The Pavlik dressing device cannot be used in teratotropic dislocation. The persistence of subluxation or subluxation after 3-6 weeks of treatment with the Pavlik dressing device should be abandoned. Infant group 6-18 months: The mainstay is closed reduction, including preoperative traction, gentle closed reduction with internal adductor severance, and incisional reduction after failed closed reduction. Most children’s femoral heads begin to ossify since 4-6 months of age, and the epiphyseal nucleus has not appeared, prohibiting closed resetting, which can easily cause ischemic necrosis of the femoral head. Early childhood group 18-36 months: surgical treatment by incisional repositioning + femoral osteotomy or pelvic osteotomy. Incisional repositioning + femoral osteotomy + pelvic osteotomy to remove soft tissue structures that prevent repositioning and achieve central repositioning of the femoral head. Children’s group 3-8 years old: the structures around the hip joint in this age group have undergone adaptive shortening and structural changes in the acetabulum and femoral head, thus requiring incisional repositioning. No further skeletal traction should be performed preoperatively to reduce the incidence of femoral head necrosis, a one-stage incisional repositioning and femoral shortening, or a combined procedure such as simultaneous pelvic osteotomy. For the treatment of DDH in older children; adolescent group older than 8-10 years old: complete bilateral dislocation with high dislocation should not be incised and reset, and total hip replacement should be considered after entering adulthood. Unilateral complete hip dislocation can be considered for incisional repositioning, and those with painful acetabular dysplasia subluxation should avoid incisional repositioning of the hip and choose appropriate pelvic osteotomy and joint osteotomy of the proximal femur for treatment, which can achieve satisfactory results.