Radiation therapy is one of the commonly used local treatment methods in breast cancer treatment. It can be applied alone or in combination with surgery, chemotherapy or endocrine therapy, depending on the condition. The common complications of radiation therapy are as follows: (1) Skin damage: During radiation therapy, the skin in the radiation field can be damaged in different degrees, and mild damage, such as darkening of the skin color, can lead to local fibrosis or even radioactive ulcers after repeated high doses in recurrent patients. For the skin in the radiation field should be kept dry and ventilated, do not wash with hot water, scratch the skin with your hands. Once skin damage occurs, mild ones can be left untreated. (2) Radiation pneumonia: It mainly occurs when the lung tissue is irradiated and co-infected. Asymptomatic radiation pneumonia can occur in the early stage, and in the later stage, fibrosis of the lung apices and mediastinum parietal and elevation of the hilum can occur, but it usually does not affect the patient’s life. It is mainly cough, chest pain, shortness of breath and fever. Acute radiation pneumonia will gradually form pulmonary fibrosis after the end of irradiation, causing irreversible damage to lung function. Its treatment is mainly high-dose adrenocorticotropic hormone combined with the application of antibiotic therapy. (3) Breast fibrosis: In order to reduce the local irradiation dose, breast tumor should be removed as much as possible. Radiotherapy is one of the main treatments for all stages of breast cancer and is an important guarantee for conservative treatment, so its advantages outweigh its disadvantages.