Lung cancer is treated by various means, but the toxic side effects after treatment have always troubled patients, among which lung injury after radiotherapy for lung cancer is a topic that should be paid great attention. Lung injury after radiotherapy for lung cancer includes early radiation pneumonia and late radiation pulmonary fibrosis, which have high incidence and are difficult to treat. The symptoms include dry cough, yellowish white sputum, shortness of breath, wheezing after activity, severe respiratory distress, purple lips, inability to lie down, progressive decrease in lung function until death from respiratory failure. Radiation lung injury not only reduces the quality of life of lung cancer patients, but also seriously decreases the survival time of patients. The pathogenesis of post-radiotherapy lung injury is complex, one is patient factor: age, whether to receive radiotherapy, chemotherapy, chemotherapy time, tumor site, patient’s basic lung function status; the other is treatment factor: dose mastery, dose control of multi-course treatment, etc. At present, the treatment of radiation pneumonia with obvious clinical symptoms includes: 1. The application of antibiotics; 4. symptomatic treatment with Chinese medicine. Anti-inflammatory drugs can relieve the symptoms initially, but with the occurrence and aggravation of radiation pulmonary fibrosis, hormonal control is also more difficult, especially when lung injury occurs during lung cancer treatment, not only the tumor is not controlled, but also the condition is aggravated. Prevention and treatment of radiation lung injury are equally important. There are many ways to prevent it, but the effective one that patients can grasp is to take traditional Chinese medicine that nourishes Yin and moistens lung, clears heat and detoxifies lung when there is no damage during radiotherapy, and apply it continuously during radiotherapy. The principle of continuous application is to differentiate and change the medication according to different periods of radiotherapy, according to the patient’s physical condition, and according to the patient’s condition. Due to various reasons, more patients take treatment only after they have developed symptoms. The tricky part is that the patient’s mass is not yet under control and lung damage appears. The appearance of lung injury interrupts the radiotherapy that was originally administered, making it impossible to continue and aggravating the disease. At this point, on the one hand, symptomatic treatment is needed, and more importantly, the progression of the tumor is controlled. Once the lung injury appears, our experience is to control the infection and hormone treatment in the acute period, and to control the tumor after the acute period, because there are few effective western medical means, mainly to treat with Chinese medicine compound soup, and it is good to adjust the prescription once half a month on average.