Cranial defects without timely repair can cause various symptoms that endanger our health and also seriously affect the appearance. Some patients will have headache, dizziness, and serious fear about the expansion and collapse of the defect, which will cause depression and low self-esteem in the long run; some patients will have poor self-control, concentration and memory loss. Moreover, long-term cranial defects can cause brain tissue atrophy and cystic changes. Therefore, for the sake of health, cranial bone repair should be performed. The time to repair cranial defects is better after 3 months of craniotomy. Although the best time to treat cranial defects is after 3 months. But it does not mean that the repair cannot be done after this time. As long as there is no head infection and no serious heart or lung disease, cranial repair can still be performed. And it is recommended to do it as early as possible to avoid health risks. Of course, cranial bone repair also requires careful selection of repair materials. At present, there are many kinds of materials for skull repair in the market, each with its own advantages and disadvantages, and there are many clinical examples of postoperative problems due to unsuccessful choice of repair materials, but titanium mesh is the most well-known and widely used in many hospitals. Although titanium mesh is an improvement over the previous traditional materials, it still has some shortcomings and defects. Fortunately, through the continuous exploration and efforts of medical experts, polyether ether ketone, or PEEK as it is commonly known, has been the perfect solution to the shortcomings of other materials. The repair will not cause any rejection by the patient and will allow the patient to achieve a better recovery. Currently, PEEK has been used to repair cranial bones in clinical practice with excellent results.