The hip joint abduction angle of infants has individual differences due to different growth and development, such as the normal angle of the hip joint of newborns is 30 to 40 degrees, which should be combined with the imaging examination. The normal angle of hip joint of newborn is 30～40 degrees, the angle of hip joint at one year old is 23～28 degrees, and the normal angle of hip joint at three years old is 0～25 degrees. Measuring the acetabular index can make an early diagnosis of hip development. If the angle is out of the normal range, it indicates hip dysplasia or dislocation, which needs to be confirmed together with imaging tests. If the baby has hip dysplasia, conservative treatment can be taken within one year of age, and surgical treatment is needed for babies over one year of age. Parents should pay more attention to observation, give the baby more food with high calcium content, and ensure sufficient sleep. It is recommended that the patient should go to the hospital in time when any discomfort occurs, and have standardized treatment as early as possible in order to reduce the adverse effects of the disease.