Cranial defects are the more common sequelae of craniocerebral injury patients after injury and surgery. Since the brain tissue loses the shielding effect of normal skull, it is easy to be injured twice, and at the same time, cranial defects can cause various symptoms and affect the appearance, therefore, many of these patients need to undergo cranioplasty, whose purpose is to make the patient’s intracranial pressure return to normal and stable as soon as possible, and to reduce the intracranial pressure due to cranial defects and drastic changes, which can damage the cerebral function. Defects with a diameter of more than 3cm often have this or that symptom, such as dizziness, headache, localized tenderness, irritability, restlessness, etc.; the patient is mostly fearful, afraid of the sun, afraid of vibration and even afraid of noisy sounds, often with poor self-control, inattention, memory loss, or depression, fatigue, reticence, and low self-esteem. The skull is concave when standing, and the external image is frightening, which can seriously affect the patient’s life and work. The only way to solve the problem is to repair the defective skull, and the timing of repair should depend on the patient’s systemic and local conditions, such as in simple depressed comminuted fracture after removing the collapsed bone fragments, the repair can be accomplished by a single operation in the same period of time. For craniocerebral injuries caused by bone flap decompression of cranial defects, generally about 3 months after the operation should be considered to repair the skull, and the earlier the repair to improve the patient’s symptoms, the more favorable, unless it is open craniocerebral injuries occurring infections, repair surgery should be postponed to more than half a year. How to repair the patient’s defective skull is the focus of neurosurgeons. After years of efforts, neurosurgeons have developed bionic bone as an artificial bone repair material and formed a personalized cranial bone repair program, which takes only 2~4 hours to operate. The program has the advantages of less bleeding, low infection rate and high activation rate.