The development of radiation therapy for tumors can be traced back to 1895, when Roentgen discovered X-rays; Becquerel followed in 1896 with the discovery of the radioactivity of uranium; in the same year, the Curie couple discovered the radioactive isotope radium. in the 1820s, X-rays as well as radium were applied to radiation therapy for laryngeal and cervical cancer, respectively; in the 1850s, cobalt 60 was used to treat malignant tumors. The machines for external radiation therapy have gone through deep X-ray machines, cobalt 60 treatment machines, and now the most widely used linear gas pedal. Based on the linear gas pedal, radiation therapy technology began to develop by leaps and bounds, experiencing simple square field irradiation, two-dimensional simulator conformal radiotherapy, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, image-guided radiotherapy, and dose-guided radiotherapy. The advancement of radiotherapy technology has enabled radiotherapy to move from low-precision general radiotherapy to the era of precise radiotherapy. With the improvement of irradiation position precision and dose precision, the patient’s tumor exposure is also more precise, and the adverse effects are reduced. The image guidance system, robot system and treatment bed system owned by the radio wave knife can control the comprehensive error of treatment within 10mm or even 2mm. Using 12 different diameters of light-limiting cylinders can make the tumor and adjacent normal tissues obtain sharper dose drop gradients, which can better protect the normal tissues around the tumor and reduce the side effects caused by radiation therapy. Take head and neck tumors as an example, after radiotherapy, patients have very serious symptoms of dry mouth and mucositis, some of them are accompanied by brain necrosis, stiff neck muscles and difficulty in opening mouth, which were the adverse effects of conventional radiotherapy in the past. Nowadays, along with the development of radiotherapy technology, the side effects are decreasing, and the dose can be better concentrated locally in both precision radiotherapy or radio-wave knife treatment. Overall, the side effects of radiotherapy are as follows: ① systemic blood reactions such as white blood cell reduction; ② gastrointestinal reactions such as nausea and vomiting; ③ there is also a local adverse reaction, for example, when irradiating the nasopharyngeal area due to nasopharyngeal cancer, the oral cavity is bound to be irradiated with a certain dose, and the oral mucosa may have ulcers, which are usually treated with drugs. If the tumor grows in the periphery when suffering from lung cancer, traditional radiotherapy may cause radiation pneumonia, and the probability of occurrence will be much lower with radioactive knife treatment. With the advancement of radiotherapy, there are less and less adverse effects. When many elderly patients cannot undergo surgery because of poor heart and lung function, stereotactic radiotherapy or stereotactic radiosurgery represented by radio wave knife can also play a very good radical or local control effect. The position of radio-wave knife in comprehensive tumor treatment is getting higher and higher.