With the development of neurosurgical treatment technology, more diseases are diagnosed at the early stage of onset, especially intracranial occupying lesions, which have the possibility of obtaining treatment when their volume is small. In this case, CT/MRI combined with stereotactic technology-assisted microsurgery to remove small lesions has its superiority compared with conventional craniotomy. 1. Applicable to resection of small intracranial lesions ① In various conventional microsurgeries, the effective retraction range of brain tissue is about 2.0 cm, regardless of near cortex or deep, and lesions below 2.0 cm in diameter can be well exposed in this range. Small lesions in this group are defined as lesions with an imaging (CT or MRI, enhanced scan if necessary) diameter ≤ 2.0 cm; ②Small lesions can be simplified by considering their center as the target point, which does not require multiple target positioning and is easy to operate; ③Small lesions have high stability when surgically removed through small bone windows. 2, precise positioning, minimally invasive resection of lesions ① conventional methods of craniotomy to remove small intracranial lesions, it is more difficult to find the lesion, often need to make significantly larger skin incisions and bone flaps, or repeatedly explore the lesion, causing significant damage to normal brain tissue; stereotactic technology can precisely locate the lesion, so that the small bone window craniotomy is possible, the small bone window can reduce the ineffective exposure of brain tissue, limit excessive stretching, reduce the The small bone window can reduce the ineffective exposure of brain tissue, limit overstretching, and reduce the damage to normal brain tissue and blood vessels, and this advantage is more significantly reflected in the removal of small lesions in functional areas. The surgery was completed under local anesthesia in 6 cases of near cortical lesions, which reduced the interference of general anesthesia on the body and was safer for the old and frail. 3. Regarding the use of CT or MRI scan, the scanning method of surgical localization should be individualized, and the nature of the lesion should be initially determined based on the medical history and clinical manifestations, combined with the available imaging data, and the decision of localization by CT or MRI scan and the need for enhancement should be made; in this group of 11 patients, the preoperative diagnostic compliance rate was 91%, and the postoperative image review showed a 100% total resection rate. 4, the surgery should pay attention to the problems ① the installation of the stereotactic head frame should fully consider the convenience of surgical access and anesthesia intubation; ② the calculation of target point coordinates should be accurate; ③ the surgery should choose the cerebral sulcus access as far as possible, avoiding the functional area and important blood vessels; ④ for deep lesions, the micro-diameter silicone tube can be placed by the guide needle as a marker to avoid the displacement of the lesion during the separation process. 5.Comparison with neuronavigation system For small intracranial lesions, framed stereotactic system, simple operation, small positioning error, stable instrument operation, but can not be real-time positioning, cumbersome process when operating multiple targets, and due to the influence of the head ring and pillar of the directional instrument, the lesion access to the skull base, posterior cranial fossa and other parts of the skull is limited.