Due to the increase of patients with heavy craniocerebral injury and the promotion of large bone flap craniotomy in primary hospitals, the number of patients with postoperative giant cranial defects is also increasing. Our hospital admitted 11 cases of patients with huge cranial defect repair from 2001 to 2006, and the repair experience is reported as follows. 1, information and method 1.1 General information: 9 cases of male, 2 cases of female; age 20-46 years old, average age 35.6 years old. Cranial defect site: 11 cases of frontotemporal top. The range of cranial defect: minimum defect 10cm×12cm, maximum defect 12cm×16cm. 7 cases of preoperative cranial defect syndrome, 2 cases of hemiplegia, muscle strength of grade II-III, 2 cases of epilepsy. Operation time: 4 cases in 3 months, 5 cases in 6 months and 2 cases in 1 year after craniotomy. 1.2 Surgical method: titanium mesh was used to cover the titanium mesh. 7 patients in this group were shaped intraoperatively according to the size of the bone window site. The edges were cut to be larger than the defect area by 1 cm, covered the skull defect, and then fixed firmly with titanium nails. The EH cranial plate was fixed to the skull with silk thread intraoperatively. 2.Results After surgery, there was no infection in the incision of 11 patients, and one patient with EH cranial plate repair had subcutaneous fluid after surgery, which gradually subsided after puncture and fluid extraction. The affected side was symmetrical with the healthy side and recovered aesthetically, and there was no pain in mastication. The symptoms of cranial defect syndrome improved significantly or disappeared after 3 months of postoperative follow-up, and the muscle strength of hemiplegic patients improved significantly to grade IV-VI after 6 months of postoperative follow-up. 1 case of epilepsy patient had significantly reduced the number of seizures. 3, Discussion 3.1 The significance of cranial defect repair: large flap craniotomy cranial defect patients are a special group in the craniocerebral injury population, their psychological burden, mental pressure is heavy. Especially fear of re-injury at the affected area, psychological fear is higher than those with small skull defects after craniocerebral trauma. Therefore, the purpose of repair is firstly to avoid re-injury of brain, to release the psychological fear, to keep the head shape normal, and to achieve the effect of plastic surgery in appearance. In addition, it has a certain promotion effect on the recovery of neurological function. The mechanism may be that the cranial repair lifts the collapse caused by atmospheric pressure and gravitational force in the large area of cranial defect after the operation, stabilizes the physiological balance of intracranial pressure, thus improves the hemodynamics of brain tissue, improves the local blood supply and oxygen supply to the brain, and promotes the recovery of neurological function. 3.2 Selection of cranial repair materials: titanium mesh and EH cranial plate were selected in this group. The advantages of titanium mesh material: easy to shape, easy to operate, firm fixation, good histocompatibility and stability, strong compressive properties, and less complications; the advantages of EH cranial plate: easy to shape, no antigenic, tensile and compressive strength close to human skull, good biocompatibility, no reaction to muscle tissue, and bone bonding with bone tissue, which is an ideal material. 3.3 Cranial defect repair after large flap craniotomy is different from small defect repair because the defect is large. The author has the following experience: shaping of frontotemporal angle and parietal nodal area: large bone flap usually has bone defects in frontotemporal angle and parietal nodal area of the skull, and these two parts are key parts of the skull shape. Preoperative and intraoperative careful observation of the defect and good shaping of these two parts are usually the key to good postoperative shape. Good temporal fixation: usually the temporal skull defect is low in patients with large flap decompression and close to the skull base, if the defect reaches the level of zygomatic arch, sometimes it is difficult to separate the temporal muscle, and it is also difficult to fix the titanium plate on the temporal bone. At this time, sometimes if the temporal bone defect is too low, we can consider fixing the lower end of the titanium plate on the zygomatic arch, which can reduce stripping the temporal muscle to increase bleeding, simplify the surgery and increase the fullness of the temporal area. This is because in most people, even though the repair achieves restoration of the cranial shape, the temporalis muscle is still sunken in shape compared to the contralateral side because of postoperative atrophy. With the lower end of the titanium plate fixed to the zygomatic arch, the patient’s postoperative appearance is closer to the fullness of the normal temporal region compared to the normal temporal region. The dura is suspended by silk thread over the repair material to reduce dead space and to prevent complications such as postoperative hematoma and effusion. Because large bone flaps usually have large defects, there is often a large cavity between the repair material and the dura mater after the repair, which can easily cause fluid accumulation and infection, etc. In the present case of EH cranial plate repair, a patient with postoperative incision pressure dressing suddenly developed headache and violent vomiting on the second postoperative day. The emergency reexamination of cranial CT showed an epidural fluid collection with a leftward shift of 0.5 cm of the neutral structure, which was considered to be caused by the pressure bandage pushing the subcutaneous fluid into the epidural. In addition, the dural suspension was not firm enough to form a dead space, and the cerebrospinal fluid leakage was not found due to minor intraoperative dural injury. The symptoms improved with the release of pressure dressing and subcutaneous fluid extraction. The subcutaneous fluid disappeared after multiple punctures and fluid aspiration, and the cranial CT was repeated 10 days later. The repair of cranial defects after large flap craniotomy not only restored the patient’s normal head shape appearance, but also reshaped the patient’s self-confidence and reversed the poor psychological state, which is extremely important to improve the patient’s quality of life.