As we all know, radiation therapy is one of the top three treatments for malignant tumors, and when it comes to diseases requiring radiation therapy, people always associate it with malignant tumors. In fact, more than 70 kinds of benign diseases can be treated with radiation therapy with unexpected effects. Every year, many patients with benign diseases recover through radiation therapy in normal treatment. In clinical work, radiation therapy for benign diseases has a history of more than 100 years, and in recent years, it has received the attention of clinical radiologists and clinical medicine experts. the questionnaire of ESRTO shows that there are 28 common diseases treated by radiation therapy, and about 70 benign diseases suitable for radiation therapy. With the increasing improvement and perfection of radiation therapy equipment and technology, the technology of precise control of irradiation dose, irradiation range, irradiation time and normal tissue protection has reached a high level in the treatment of benign diseases. 1.Treatable diseases Under the guidance of the U.S. Radiation Therapy Committee for Benign Diseases, the common diseases included in the treatment scope of radiation therapy such as Graves’ eye disease, skin keloid, splenomegaly, hypersplenism, tenosynovitis, frozen shoulder, osteoarthritis, hemangioma, common warts, corns, subxiphoid warts, ringworm, beard sores, hirsutism, parotid fistula, pancreatic fistula, axillary odor, chromatosis, psoriasis, neurological dermatitis, eczema, vulvar pruritus, ankylosing spondylitis, pigmented choroidal synovitis, ectopic ossification, eosinophilic granuloma, lymphoproliferative eosinophilic granuloma, refractory idiopathic thrombocytopenic purpura and autoimmune diseases (rheumatoid arthritis, lupus erythematosus), etc. 2.Caution Radiation therapy for benign diseases should also be cautious and requires strict control of indications. The quality of radiation, total dose, treatment time, and basic factors of risk of occurrence should be fully considered before treatment. Pay attention to protect the surrounding normal tissues and avoid late damage to important organs. The benefits and risks of treatment should be carefully evaluated in infants and children, and radiotherapy should be withheld unless necessary. In addition, we should make a comprehensive comparison with other treatment methods, accurately analyze the advantages and disadvantages, fully utilize the therapeutic effect of radiation, and minimize the toxic side effects. Radiation therapy is generally considered only when surgery and drugs are not effective.