Square skulls in children are primarily a symptom of vitamin D deficiency rickets, which is caused by insufficient intake of vitamin D, coupled with particularly rapid growth and development in children. At this time, children will be calcium deficiency, frontal bone and parietal bone on both sides of the bone-like tissue hyperplasia, symmetrical bulging, the formation of square skull. A square skull is a box-shaped head that can be seen from the top of the child’s head downward. The square skull in children should be treated with timely intervention, such as applying vitamin AD drops and calcium gluconate for calcium supplementation. After active treatment, the square skull in most children can be relieved to different degrees.