Neurosurgical endoscopy has long been limited to intracranial cystic fluid lesions. The configuration of an expensive endoscopic system that can only treat cystic fluid lesions is a little too costly for the average hospital. In fact, endoscopic neurosurgery is indicated for all lesions in the cranial cavity (cystic and non-cystic fluid lesions). Compared to microscopic surgery, endoscopic surgery is the least invasive because the endoscope can be extended into the body for close viewing with no dead space and no attenuation of light. However, endoscopic surgery for non-cystic fluid lesions has some problems to be solved. 1, the establishment of the working channel of endoscopic surgery Intracranial microsurgery is like a well (pit) operation, the endoscope focal length is short, reaching into the body for close observation can only see the bottom of the pit, the instruments in and out of the surgery may damage the normal structure, the establishment of the working channel of endoscopic surgery is not only the need to expose the lesion, but also the need to protect the normal tissue. Minimally invasive (ϕ<10 mm) endoscopic procedures for intracranial cystic fluid lesions are most accepted because of the manufacturer's special trocar for them; small invasive (ϕ<40 mm) endoscopic procedures for intracranial non-cystic fluid lesions are questioned because of the unavailability of a ready-made trocar. Why does the working channel have to be a closed, cylindrical trocar? A simple approach can be used to create a working channel for intracranial microsurgery. For this purpose, the cranial cavity can be divided into extracerebral and intracerebral regions: the extracerebral region includes the skull base, the falx region and the cerebellar curtain region, and the intracerebral region includes the intracerebral parenchyma and intracerebral ventricles. In the extracerebral region, the brain tissue is retracted by a pressure plate to form the working channel for microsurgery; in the intracerebral region, the pituitary speculum with the addition of a flexible shaft retractor clamping blade is used to hold open the working channel for microsurgery. The pituitary speculum enters the trabecular tract and then props it open with minimal damage to normal brain tissue; the purpose of adding the soft-axis retractor gripping blade is to keep it stable using the soft-axis retractor. If the pituitary speculum double lip is put into latex finger sleeve, it will form a closed working channel after propping open, and the exposure and protection will be more adequate. 2.Endoscopic support The intracranial microsurgery is characterized by a single two-handed operation, which requires a good way to support the endoscope. The first thing that comes to mind is definitely a special stand for the endoscope, but the problem is that it is expensive and not to mention that it is also troublesome to adjust the observation angle and progress of the endoscope during the surgery. The endoscope-microscope digital camera is lightweight and handheld endoscope for operation, which is both convenient and cost-free, the problem is how to ensure two-handed operation. The solution is simple, lengthen the suction device and tie it together with the endoscope rod, you can hold the endoscope and suction device with your left hand, and alternate the bipolar electrocoagulator or other instruments with your right hand, still a two-handed operation. 3, endoscope cleaning Endoscope focal length is short, reaching into the body to observe blood up close will contaminate the lens, affecting the operation, the surgery is also dangerous. To keep the endoscope clean, a special pulse flusher can be used, but the cost is too high. If a lateral ventricle-abdominal shunt device is used, pulse flushing can also be achieved and the cost is low.