Radiation therapy includes intracavitary and extracorporeal irradiation; the equipment used includes radium ingots, X-ray machines, cobalt guns, and nowadays, gas pedals are mostly used, as well as post-loading machines and various “photon knives” and “X-knives” developed in recent years. It can be used as adjuvant treatment before and after surgery to improve the surgical resection rate and long-term survival rate after surgery, and radiotherapy can also be used for inoperable or recurrent metastatic squamous carcinoma. Radiotherapy is divided into simple radiotherapy and comprehensive radiotherapy. Simple radiotherapy is divided into radical radiotherapy and palliative radiotherapy. It can be decided according to the pathological type of lung cancer, the extent of lesion, whether there is metastasis, lung function and general condition. Comprehensive radiotherapy is a treatment combining radiotherapy with surgery and chemotherapy, which can improve the survival rate than any one treatment alone.