Developmental hip dysplasia is one of the more common congenital orthopedic disorders in children, with an average prevalence of 3.9%, and children who are not treated grow up with a limp disability. Early detection of this disease and early intervention are of great significance to avoid disability to the greatest extent possible. The best results are achieved when the disease is diagnosed and treated before the infant is 6 months old, and it usually takes only 2 to 3 months to return to normal in a special dressing girdle. However, more than 90% of the children in clinical practice are found to be over 1 year old or 2 to 3 years old due to unstable walking, duck walk, limp or even calcium deficiency, at which time many of them have dislocated or deformed joints, which is not only complicated to treat, costing up to 10,000 yuan or more and causing more pain to the children, but also greatly reduces the treatment effect, and some of them may have lifelong disability or serious impact on their quality of life. Some children may also suffer from lifelong disability or develop femoral head necrosis that seriously affects their quality of life and require artificial hip replacement. For this reason, there is a strong emphasis on early screening for this disease and timely treatment and recovery. Infants who have not been screened should also go to the hospital if they find asymmetrical skin folds on the inner thighs or unequal length of the lower extremities, as well as a popping sound or popping sensation when pulling on the lower extremities. Early manifestations of developmental hip dysplasia: Asymmetric thigh skin folds: Unequal length of both lower extremities, unequal width of both hips.