Gamma knife is a stereotactic radiosurgery technique, which refers to the one-time focus of high-energy radiation on a limited target area of the skull while the amount of tissue outside the target area is very slight, thus forming a neatly edged necrotic foci, shaped like a knife cut. It is characterized by one-time high dose, mainly applied to small intracranial lesions, with non-invasive, safe, precise positioning, simple treatment, few complications and fast recovery. This technology has become a mature and important branch of modern neurosurgery, modern radiation oncology after nearly 40 years of development. Wang Hongwei, Department of Neurosurgery, Affiliated Hospital of Inner Mongolia Medical University As the sunlight converges on the focal point after the magnifying glass, the match at the focal point will be ignited, while the match not at the focal point is unharmed. The collimation device of gamma knife is like a magnifying glass, focusing gamma rays and forming a focal point at the center of the shell sphere, so that we can accurately transport the lesion to the center of the sphere through the principle of stereotactic orientation and give the lesion a planned dose of irradiation.