Cranial repair surgery in children is used to treat patients with defects caused by cranial trauma and brain surgery. There are also patients with congenital cranial defects due to developmental or ossification disorders in the embryonic period. Cranial repair is a relatively routine procedure in neurosurgery and can be performed after a child reaches the age of three years according to the neurosurgery guidelines for cranial repair. After the age of three, the child’s skull basically grows more slowly, and the skull grows along the bone suture, and the size of the bone window basically does not change. Moreover, children are at an active age, with little awareness of self-protection, and are vulnerable to external injuries; long-term cranial defects are also likely to cause neurological damage: therefore, early cranial repair is needed. The choice of skull repair material: 1, titanium mesh material, i.e. titanium alloy material. It is a material with high usage rate at present. Its advantage is that it is cheap and cost-effective. Non-corrosive and firm. It can be forged and the cosmetic effect is better compared with bone cement and so on. But at the same time there are certain risks, the problem of its metal material causes it to have higher thermal conductivity and poor insulation, which may cause sensitivity to hot and cold reactions, and children may be more sensitive to such hot and cold reactions. In addition, the surgery of skull repair with titanium mesh is an overlay surgery, which is more irritating to the scalp. It is also less histocompatible and less resistant to pressure, so it causes it to be not strong enough and easily deformed by force. Children are playful and do not know how to protect themselves, and it is more likely to cause secondary injuries if the material is not strong enough. At the same time, the material will also have metal artifacts, which may affect medical examinations, such as CT resonance, causing diagnostic interference. So it is not the choice of skull repair material for children. 2.Polyetheretherketone material, also known as peek material. It is the current material for treating cranial defects. It is also one of the materials suitable to be selected for skull repair surgery. Polyetheretherketone is a kind of polymer material which is comparable to human body’s own cranial bone. It is more biocompatible. It is strong but very elastic and tough, more resistant to impact and better protection. This effectively avoids the risk of accidental impact by children. Unlike titanium mesh material for overlay surgery, skull repair surgery with polyetheretheretherketone is an embedded surgery and more comfortable. Moreover, compared with titanium mesh material polyetheretherketone material basically does not conduct heat and has strong insulation properties. It avoids the sensitivity to hot and cold reactions caused by cranial repair surgery with titanium mesh. There is also no postoperative infection and no rejection. Rays can be transmitted without forming artifacts. Moreover, polyetheretherketone is a material that can be plasticized in three dimensions and can be customized for three-dimensional reconstruction according to the different needs of patients. The design is made according to the patient’s brain CT data, and the 3D printing technology is used to produce a cranial bone that perfectly matches the bone window after the cranial repair and its own cranial bone fit perfectly, beautiful and natural. So whether it is a child’s skull defect or an adult’s skull defect, a good choice of material is polyetheretherketone material. The material is better adapted to children’s cranial growth and development relative to children.