Surgery for glioma is one of the most common procedures in neurosurgery, but the results vary from one neurosurgeon to another. In most cases, surgical resection is the initial and most important treatment for glioma, which not only needs to remove as much tumor as possible, but also protect the important neurological functions, and provide the basis and support for later radiotherapy and molecular biology treatment, so the success or failure of surgery directly affects the quality of life and prognosis of patients. 1.The principle of precise tumor location before surgery Before surgery, we should make a comprehensive assessment of the location and infiltration range of tumor based on the information of cranial enhanced MRI, and refer to the imaging information of fMRI and DTI to make a preliminary judgment of the adjacent relationship between tumor and important brain functional areas and nerve fiber pathways, as well as the possible resection range. The principles of selecting the appropriate surgical access should be taken into consideration that glioma is a malignant tumor, and for most patients, tumor recurrence is inevitable after surgery. Therefore, during the first surgery, the flap design should not only be designed for this tumor removal, but also take into account the need for secondary surgery after tumor recurrence as much as possible. It is worth emphasizing that the so-called “locking hole” or small bone flap craniotomy is not suitable for surgical resection of glioma. For the first operation, the flap design should generally exceed the tumor margin by 2-3 cm, and the surgical incision should preferably not be located on the surface projection of important functional brain areas, such as the central sulcus and the precentral gyrus. For tumors adjacent to the anterior and posterior central gyri, flap design should be appropriate to reveal these functional areas for better intraoperative identification and protection. The principle of accurate intraoperative judgment + protection of functional areas In addition to the traditional anatomical knowledge to judge the important functional areas of the cerebral cortex, it is better to use modern anesthesia and neurophysiological monitoring techniques. Arousal anesthesia or awake anesthesia has high requirements for both anesthesiologists and patients and should be used with caution, and is currently only suitable for monitoring and protecting cerebral language areas [4]. For the determination of somatomotor and sensory areas cortical motor evoked potentials and somatosensory evoked potentials are best used [5], and such monitoring methods were used in four patients in this group, and preliminary observations confirmed that both monitoring methods are safe and effective, but also require close cooperation between the anesthesiologist and the electrophysiology technician. Since the patient does not need to be awake, just no inotropic drugs are used, thus greatly increasing the safety of the procedure, but there are some deficiencies in sensitivity, which may be related to the number of peripheral electrodes we use, to be further observed and explored in the future. In addition, intraoperative real-time monitoring with B-mode ultrasound is not only helpful to judge the location of tumor, but also the extent of tumor resection, and the operation is simple and easy, especially for tumors in deeper locations. The principle of protecting important blood vessels is the basis of tumor development and malignant transformation, so the surgery should not only remove tumor cells, but also block the supply blood vessels of tumor. The “passing” vessels should be protected in general, especially the thick drainage veins. For glioma located in relatively non-functional area, it is better to choose the whole resection method, especially for the high-grade tumor with rich blood flow. However, for tumors located in functional area or adjacent functional area, the method of intratumoral block resection or combination of block resection and block resection should be adopted to avoid or reduce the damage of important neurons and nerve fibers. 6.The principle of appropriately expanding the tumor resection range A part of glioma is based on expansive growth, especially low-grade glioma. The boundary of this part of tumor is similar to that provided by preoperative MRI, and the resection range is better determined under microscope, and the effect of surgery is also best. For tumors far from important brain functional areas, the sulcus approach is the best when choosing the access to the tumor. If the tumor is confined to one or two brain gyri, the entire involved brain gyri can be completely resected along with the tumor. For tumors with predominantly infiltrative growth, the tumor can be seen microscopically to infiltrate distally along the white matter fiber bundles or extravascular gaps, which may not be fully revealed on preoperative imaging. After resection of the main body of this type of tumor, the distally infiltrating tumor should also be microscopically resected in blocks. Under the microscope, the texture and appearance of this infiltrating tumor is often similar to that of the main body of the tumor, generally grayish in color and more prone to bleeding than normal brain tissue. For tumors that invade the ventricular wall, preoperative MRI can reveal an enhanced ventricular wall and choroid plexus. When resecting such tumors, it is better to remove the involved ventricular wall and choroid plexus together. 7. The principle of reasonable use of external drainage For huge glioma, especially malignant glioma, the exudate in the surgical residual cavity after tumor resection is more and the protein content is extremely high, which cannot easily participate in the normal cerebrospinal fluid circulation and form a dense cavity locally, and then produce obvious occupying effect. If an external drainage tube is left in the residual cavity, the exudate can be drained out in time, which can reduce the intracranial pressure and also reduce the use of postoperative dehydration drugs. For huge tumors after surgical resection, due to the obvious collapse of brain tissue, subdural or epidural fluid accumulation or even intracranial hematoma is very likely to occur after surgery, in such cases, an epidural drainage tube can be left to avoid intracranial fluid accumulation or hematoma. According to our experience, it is appropriate to leave the drainage tube in place for 3-5 days. Although it is rare for gliomas to metastasize outside the skull, many tumors can spread along the cerebrospinal fluid in the ventricles or subarachnoid space, especially mesenchymal astrocytomas and glioblastomas [6]. Therefore, the “no-tumor” principle should be observed throughout the procedure, and it is best to use separate surgical instruments and tampons for tumor removal. For tumors that do not involve the ventricles, the ventricles should not be opened during the operation, and saline irrigation should be performed in a timely manner to remove the water and not to spill it outside the tumor nest. For tumors involving the ventricles, it is better not to flush, so as not to cause tumor dissemination along the ventricles. 9. The principle of preserving bone flap as much as possible Bone flap repositioning is crucial to improve the quality of life of patients. If a piece of skull bone is missing, the patient will not dare to participate in various social activities, which will have a negative impact on the patient’s psychology, and the pessimistic and negative emotions will directly affect the patient’s life and even make the patient unable to work. Therefore, unless as a last resort, it is generally necessary to try to reset the bone flap. 10, try to restore the principle of the original appearance surgery will bring a certain blow to the patient’s physical and mental, but if the original appearance of the patient can be restored, the appearance is not easy to see that the patient has received surgery, it will have a positive impact on the patient’s psychology, enhance the patient’s confidence in life and work. Therefore, as a good neurosurgeon, we should not only focus on the intracranial operation, but also on the impact of the surgery on the patient’s appearance, and try to minimize the impact of the surgery on the patient’s appearance.