Radiotherapy is an important tumor treatment. Its basic principle is that tumor cells are more sensitive to radiation damage than normal tissues, and the repair after damage is slower than normal tissues, thus the ionizing and destructive effect of radiation on cells can be used to kill tumor cells. Radiotherapy is applicable to the treatment of many sensitive types of tumors. According to the treatment purpose, it can be divided into two categories: radical radiotherapy and palliative radiotherapy, which are chosen according to the condition. In radiotherapy, radiation can cause radiation damage to normal tissues and trigger a variety of systemic and local injuries and blood reactions. Therefore, before deciding on radiotherapy, we should fully weigh the advantages and disadvantages of radiotherapy, and make careful arrangements according to the tumor type, site and treatment purpose to choose the appropriate radiation, dose and irradiation method in order to improve the efficacy and reduce the damage to normal tissues. In clinical practice, we call this kind of radiotherapy method of irradiating 2 or 3 times a day with an interval of 4-6 hours, and the daily dose of irradiation is smaller than the conventional 200 higorie (mostly 115-120 higorie per time), the total course of treatment is unchanged or slightly extended, and the total dose is increased as “hyper-segmentation radiotherapy”, which is a useful improvement to improve the radiotherapy effect of tumors. It is a useful improvement to improve the effectiveness of radiotherapy for tumors. The benefits of this treatment include improved tumor control and, hopefully, improved patient survival. At the same time, there is no increase in damage to normal tissues and organs from radiotherapy in the long run. This treatment is mainly beneficial for slower growing tumors such as head and neck tumors and bladder cancer, but not for tumors that are sensitive to radiotherapy such as lymphoma and seminomatous cell tumors. Of course, during this treatment, the patient’s reaction to radiotherapy at that time may be aggravated, for example, when this method is applied to patients with recurrent nasopharyngeal cancer, the possibility of redness, swelling or even rupture in the patient’s mouth is much greater than the normal once-a-day radiotherapy.