Asymmetry of leg lines can be seen in physiological factors, no special treatment is needed; if it is caused by developmental hip dysplasia, lower limb muscle tone and other pathological factors, it can be corrected by orthopedic appliances, reset, fixation agent and other surgical treatments. 1. Physiological factors: babies in the process of growth and development will appear asymmetric leg lines, if there is no long and short legs, popping and other abnormalities, this is a normal physiological phenomenon, most do not need special treatment, observation and follow-up can be. 2. Developmental hip dysplasia: most of the children will have asymmetric leg lines. For children with developmental hip dysplasia aged 0-6 months, hip flexion and abduction brace or support is the main treatment method, and the most commonly used is the movable Pavlik brace (dress brace). The most commonly used is movable Pavlik brace (dress brace). 6~18 months old children can be treated by closed reset and incision reset, closed reset is preferred; 18~24 months old children need to be treated by surgery. 3. Poor muscle tone of the lower limbs: If the lack of oxygen and ischemia in the brain affects the development of the nervous system, resulting in poor muscle tone of the lower limbs, there will be asymmetry of the leg lines. It is necessary to treat the primary disease first. Those who seriously affect the appearance and movement need to follow the doctor’s advice to carry out rehabilitation training, or wear fluke appliances for treatment. There are many causes of asymmetry of leg lines, and it is recommended that babies with asymmetrical leg lines be seen by a specialist for evaluation and treatment in order to avoid delays and adverse consequences.