The baby’s shaking legs may be caused by the imperfect development of nerves, or may be caused by hypocalcemia, pediatric epilepsy and other diseases. 1. Neurodevelopment is not yet perfect: due to the baby’s age, its neurodevelopment is not yet perfect, the control of muscle function is not sound, when frightened, external stimuli, may appear muscle tremor, manifested as shaking legs. 2. Hypocalcemia: Baby shaking legs is also considered to be caused by hypocalcemia. Hypocalcemia can be caused by vitamin D deficiency, vitamin D dependence and other factors. Affected children may develop muscle spasms, which are manifested by involuntary shaking of leg muscles, or twitching of hands and feet, eyelids or corners of the mouth. 3. Pediatric epilepsy: Pediatric epilepsy may be caused by factors such as heredity, abnormal brain development, brain injury, and infection. Affected children may experience involuntary twitching of a part of the body, which may be manifested as leg shaking. Baby shaking legs may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.