The rapid development of modern minimally invasive neurosurgery is inseparable from the progress of imaging technology and the invention and application of a variety of high, precise and advanced technical equipment, of which the neuronavigation system is one. The accurate localization of lesions in the deep cranial brain, especially in the brainstem, thalamus and basal ganglia, has always been a challenge, so the intraoperative navigation technology was born. In the late 1980s, neurosurgeons, imaging experts and computer scholars successfully designed and developed the “Neurosurgical Microsurgery Navigation System” through multidisciplinary cross-collaboration. The system uses computer graphics technology to process radiological imaging (CT, MR, DSA, PET, etc.) data and reconstruct two-dimensional or three-dimensional medical image models to help surgeons perform virtual demonstrations of surgical operations and plan surgical approaches before and during surgery, breaking through the constraints of existing surgical instruments and auxiliary equipment to help operators complete a series of complex and delicate operations on deep nerve tissue, and to integrate It helps the operator to complete a series of complex and delicate operations on deep nerve tissues, reducing unnecessary damage to normal neurovascular structures around the lesion to a minimum. Recently, the U.S. COMPASS Cygnus electromagnetic navigation system introduced by our neurosurgery department was installed and put into clinical use, which is the third one in China and the first one in Northwest China. Electromagnetic navigation is the latest research and development of the third generation of navigation system, compared with the previous optical navigation system is huge, heavy equipment, visual obstruction and other unfavorable factors, the advantages of electromagnetic navigation focus on: 1, small size, easy to move, there is portability: this feature greatly alleviates the operating room space shortage situation, facilitate the sharing of equipment in the operating room; 2, no visual obstruction: navigation work requires less space, no need to Lift or move the microscope and other equipment, to a certain extent, it can be said that “do not feel the presence of navigation”; 3, no reference ring: electromagnetic navigation due to the design concept progress, reduce the incidence of systematic image drift, the error is smaller; 4, navigation accurate average image matching error of only 1.54mm: accuracy than before greatly improved ;5, good device compatibility: its DC magnetic field range only covers the perioperative field, which does not affect the normal use of other devices applied intraoperatively. Intraoperative navigation system can be used for: various intracranial occupying lesions (including tumors, cysts, abscesses, etc.,, cerebrovascular malformations, epilepsy, transsphenoidal pituitary mass removal, skull base tumors, malformations (soft tissue or bony,,, intracranial foreign body removal, biopsy or drainage, ventriculoscopic surgery, etc.