Stereotactic neurosurgery technique, referred to as brain stereotactic surgery, refers to the use of the principle of stereotactic positioning at one point in space to first find out the coordinates of an anatomical structure or lesion in the brain, i.e., the target point in the cranial cavity, and determine its precise location. The aim is to study, diagnose or treat brain diseases. Neurosurgeons are often troubled by the potential for severe side trauma when performing brain surgery, as the cerebral cortex must first be incised to discover the lesion beneath. If the lesion is small and deep, it will be very difficult to find it directly; if the lesion is located in an important functional area, it is difficult to avoid damage by craniotomy; if the target point of exploration is a normal tissue structure, it is even more impossible to distinguish it under direct vision. Therefore, the introduction of stereotactic surgery is to solve the above mentioned difficult problems. The main features of this technique are precise positioning and low invasiveness, and it is playing an increasingly important role as an important component of neurosurgery. The clinical applications of modern stereotactic surgery include functional neurosurgical diseases and various occupational diseases in the brain. The treatment of functional neurosurgical diseases was the earliest attempt of stereotactic surgery, and it can be said that it accompanied the whole process of stereotactic surgery development; while the treatment of various occupying lesions in the brain as the focus of stereotactic surgery is only in the last decade or so. At present, for functional neurosurgical diseases, the scope of brain stereotactic surgery includes: tremor palsy, torsion spasm, chorea, tardive dyskinesia, throwing syndrome, epilepsy and intractable psychosis and pain. The rapid development of imaging techniques such as CT, MRI and PET in the last decade has led to the development of the localization of nucleus accumbens destruction from the indirect measurement of nucleus accumbens on X-ray ventriculography to the direct measurement of nucleus accumbens at the CT and MRI level, which is quite accurate for nucleus accumbens target localization. In addition, the use of positive micro-electrode stimulation during surgery followed by nucleus destruction and the application of “cellular knife”, the lesion destruction can be precisely limited to the cellular level; furthermore, the efficiency of functional brain stereotactic surgery has been improved. Intra-stromal radionuclide brachytherapy using brain stereotactic surgery has become a major tool in the comprehensive treatment of brain tumors; in some cases, it can be used as an alternative to surgical resection, such as cystic craniopharyngioma. Most of them are suitable for intracerebral cystic lesions, and β-ray isotopes such as phosphorus 32 or yttrium 90 are generally chosen as irradiation sources for cystic lesions, which have good efficacy on the cyst wall due to their short penetration distance and little damage to the surrounding normal brain tissue. After brain stereotaxy, intra-tumoral irradiation treatment with iridium post-mounted Y-ray therapy machine is effective for deep brain substantial small tumors. Although CT and MRI can detect intracerebral lesions, they cannot make a histological diagnosis, whereas a pathological diagnosis is sometimes necessary to determine the patient’s treatment plan. The positive rate of stereotactic surgical biopsy has been reported to be 91% – 96%, of which about 1/5 of patients cannot be diagnosed by relying on clinical symptoms, laboratory and imaging tests. This shows that stereotactic biopsy of deep brain lesions has become an important tool to confirm the diagnosis of neurological diseases and to determine the treatment. Under the guidance of CT, stereotactic puncture, aspiration and drainage of hypertensive intracerebral hematoma can be performed under local anesthesia, which is a simple and agile operation with little pain to the patient and little interference to the heart, lungs and kidneys. In addition, brain stereotactic surgery can also be used for intracerebral foreign body removal, brain parasite removal, brain tissue transplantation, extraction and drainage of deep brain abscesses, intra-tumoral chemotherapy of brain tumors, radiofrequency treatment and intracerebral tumor resection combined with endoscopy. With the development of radiological imaging and the improvement of treatment technology, small lesions in the brain and lesions in important functional areas are becoming more and more common and are expected to be treated by neurosurgeons through stereotactic surgery. Today, brain stereotactic instruments are as essential to neurosurgery as operating microscopes, ultrasonic surgical aspirators, and laser knives. There is no other technology other than stereotactic technology that can achieve high precision positioning within 1mm. Stereotactic surgery can address small intracerebral lesions that are not suitable for craniotomy, deep lesions, multiple lesions and lesions located in important functional areas. As far as the lesion site is concerned, there is no limitation for stereotactic surgery, whether it is located in the brain, cerebellum or brainstem. It is clear that for elderly and frail patients, stereotactic surgery has the advantage of being less invasive. Brain stereotactic surgery is safe and reliable, and in recent years, its surgical mortality rate has been reduced to 0%-1%, and the disability rate is only 1%-3%. At present, stereotactic surgery in many foreign hospitals has accounted for more than 30% of neurosurgery, and many countries or regions have established stereotactic and functional neurosurgery centers or institutes, specializing in the study of stereotactic surgery for brain diseases. The International Stereotactic Society was established in 1961, which has promoted the continuous development of international stereotactic technology. In China, stereotactic surgery is gradually becoming popular, and professional journals about this field have been published one after another. In 1996, the Society of Neurosurgery of the Chinese Medical Association formally established a professional committee of stereotactic and functional neurosurgery.