Radiotherapy for lung cancer is to destroy the genetic material necessary for the cells of malignant tumors in the process of proliferation through high-energy rays to stop their division and proliferation, so that malignant tumor cells cannot overproliferate while protecting normal cells as much as possible. I. Radiotherapy steps 1. judge the patient’s stage and clarify the radiotherapy plan; 2. locate the radiotherapy location and determine the radiotherapy scope by doing CT and MRI; 3. determine the radiotherapy dose and outline the radiotherapy area for the patient according to the CT results; 4. carry out reset and radiotherapy. Second, the commonly used methods 1, curma knife, radio-spectral knife, plastic knife: through ionizing radiation, destroy the DNA in the nucleus, single high dose or multiple times less dose radiotherapy. However, this situation requires relatively fixed lesions, which cannot be too large or close to the trachea and esophagus, otherwise it will cause damage to local tissues; 2, general radiotherapy: routine division of the line, you can choose relatively large lesions, which is due to the number of times, each dose is relatively small, which can reduce the field of view and also effectively reduce the damage to the lung parenchyma. Caution 1, during radiotherapy, ensure a balanced intake of nutrition, as well as regular rest and relaxation, which can enhance the immunity of patients and reduce the adverse complications caused by radiotherapy; 2, when radiotherapy, it is recommended to use cotton soft underwear, try to choose loose, comfortable, warm, easy to put on and take off clothing, and avoid exposing the radiotherapy site to the sun; 3, after radiotherapy, pay attention to the treatment and control of complications. After radiotherapy, pay attention to the treatment and control of complications. Doctors try to do a good job of education, and instruct patients to conduct regular reviews to ensure that the progress of the disease and the effects of radiotherapy are continuously tracked.