First, the basic composition of the neuroendoscope The current neuroendoscope can be divided into two types: rigid endoscopy and soft fiber endoscopy. Rigid endoscopes can be divided into ventriculoscopy and skull base endoscopy, with ventriculoscopy being used for intracerebroventricular operations and skull base endoscopy being used for skull base neurosurgery. A rigid endoscope transmits images through a set of cylindrical lenses, while a soft fiber endoscope transmits images through finely arranged optical fibers. A rigid endoscope produces a clearer image than a soft fiber endoscope, which can be bent to the surgical intent without any compromise in image quality. The endoscope has a working trocar with one, three or four working channels, in which the instrument channel allows the passage of laser blade fibers and working instruments such as monopoles, bipoles, microscissors and microclamps, which are used with the endoscope. Rigid endoscopes are available with various field of view angles such as 0°, 30°, 45°, and 70° for intraoperative observation, and the appropriate angle of endoscope should be selected and prepared as needed prior to surgery. Although it is possible to view the operative field directly through the endoscope itself, it is better to perform the procedure through a surveillance system. The endoscopic surveillance system consists of a camera, a monitor and a cold light source. There are single-chip cameras and triple-chip cameras, the latter providing clear and realistic images with a resolution greater than 800 lines. The cold light source has halogen light source, mercury vapor light source and xenon light source, which provides sufficient illumination to the operating field through the conduction of the fiber-guided beam connected with the endoscope. The monitor is usually a screen monitor. Endoscopic operation can be done in two ways: hand-held operation and mechanical operation. Mechanical operation refers to the use of mechanical fixation or pneumatic fixation methods to fix the endoscope on a stand, which can facilitate the operator to operate the surgical instruments with both hands. Second, the indications for neuroendoscopic surgery With the continuous development of neuroendoscopic manufacturing process technology, the scope of application of neuroendoscopy has been expanded. At present, the application of neuroendoscopy in the field of neurosurgery can be divided into two categories: cranial and spinal. （The cranial cavity can be divided into two parts: intracerebral and extracerebral. The intracerebral part includes the ventricular system and brain parenchyma, while the extracerebral part includes the brain pools, subarachnoid space and skull base cavity. Most intracerebral neuroendoscopic procedures involve the ventricular system because the ventricular system is filled with clear fluid, which provides a good visualization condition for endoscopic procedures. (1) Ventricular system The application of neuroendoscopy in the ventricular system includes intraventricular tube surgery, recanalization after obstruction of the ventricular end of the shunt, intraventricular cystotomy (e.g. arachnoid cystotomy), triple ventriculostomy for obstructive hydrocephalus, tumor resection (e.g. gelatinous cystotomy) and biopsy. (2) Brain parenchyma Since neuroendoscopic operation requires a certain cavity gap, intracerebral parenchyma is applied after corticostomy using a special dilator in order to perform surgery for brain parenchymal lesions. Currently, it is mainly used for intracerebral hematoma and cystic tumor. 2. Extracerebral The extracranial space in the cranial cavity includes the subarachnoid space and the cavity of the skull base. Subarachnoid applications include endoscopic arachnoid cystotomy, endoscopic microvascular decompression and endoscopic-assisted aneurysm clamping. Skull base procedures include endoscopic transsphenoidal sinus saddle area tumor resection, endoscopic transsphenoidal cerebrospinal fluid nasal leak repair and endoscopic transseptal optic nerve decompression. (B) Spine The spinal system can be divided into two parts: epidural and intradural, and the intradural can be further divided into intraspinal and extradural. 1. Subdural Intramedullary neuroendoscopy is most often applied to spinal fluid, through which the septum causing fluid in the central canal can be identified and opened. Endoscopy can also be applied to biopsy, and resection of intramedullary tumors in and around the central canal. The subarachnoid space present in the extramedullary dura is also suitable for fine diameter fiberoptic endoscopic manipulation, so it can be used for extramedullary arachnoid cysts or subarachnoid cysts caused by spinal cord surgery adhesions. The latter is the most promising part of neuroendoscopic spinal applications, as many neurosurgeons abroad have already adopted endoscopic percutaneous minimally invasive surgery for cervicothoracic and lumbar disc herniation. Paraspinal tumors can also be removed using thoracic and abdominal endoscopic manipulation techniques.