As we all know, it is significantly better to prevent the occurrence of diseases than to treat them after they have occurred. Although the process of disease prevention involves sacrificing some hobbies and hobbies and some so-called “enjoyment”, and there are also financial expenses for both society and individuals. But it is worth it than the suffering caused by the disease. Usually, cancer prevention is divided into three levels: primary prevention, which refers to the prevention of the cause of the disease; secondary prevention, which refers to early detection, early diagnosis and early treatment to improve the cure rate and reduce the mortality rate; and tertiary prevention, which refers to the reasonable and effective treatment of cancer patients to improve the quality of life and prolong the survival period. I. Primary prevention of lung cancer is etiological prevention, which aims to prevent the occurrence of cancer. It aims to prevent the occurrence of cancer by taking preventive measures against specific cancer-causing and cancer-promoting factors such as chemical, physical and biological factors, as well as in vivo and external pathogenic conditions: 1. Air pollution The smoke, dust and chemical gases produced by industrial production, as well as the exhaust of automobiles, are discharged into the air to form air pollution. After people inhale it, it causes inflammation and damage to the respiratory system, and forms the basis for cancer in the lungs of people with high susceptibility. Protecting the environment and improving atmospheric air quality is both the responsibility of government departments and also requires the participation of the general public and more public opinion supervision. At the same time, the creation of a small environment is also very important, such as the use of environmentally friendly interior decoration materials, to strengthen the effective ventilation in the room, etc. 2.Control smoking. It has been confirmed that smoking is the most important cause of lung cancer. There should be a variety of ways to control people’s smoking, such as: the development of laws and related regulations; increase the price of tobacco taxes and cigarettes, the country is already in the process of carrying out; strengthen publicity, smoking is harmful to health, quit smoking can prevent disease, cancer health education. Take effective protective measures when working with asbestos, dust, etc. to prevent fine particulate matter from entering the lungs. Try to avoid exposure to inorganic arsenic compounds, radon gas, chromium and other harmful substances. 3.Lifestyle and dietary habits. Studies have confirmed that many kinds of fruits and green leafy vegetables, etc. have preventive effects on lung cancer. The key to diet is to pay attention to balanced nutrition and eat foods with high protein, high vitamin, high fiber, proper fat and calories. Do not eat moldy and spoiled food, minimize frying, deep-frying, fumigating and baking food, and have seven or eight minutes of fullness at each meal. Adhere to physical exercise, regular rest and rest time, sufficient sleep. 4, a good psychological state. Bad emotions such as frustration, disappointment, depression and anger can negatively affect the endocrine system and immune system, and the number of immune cells in the body will be reduced, which will easily lead to cell mutation and induce cancer. Secondary prevention of lung cancer From the clinical stage of lung cancer, the 5-year survival rate of early stage lung cancer patients after surgery is significantly higher than that of middle and late stage patients. Early detection, early diagnosis and early treatment play an important role in the secondary prevention of lung cancer. For the sudden appearance of irritating cough, blood in sputum, chest discomfort, chest pain and other symptoms, it is necessary to go to hospital for examination as early as possible. When symptoms such as shortness of breath, fever, emaciation and hoarseness appear, it is already the advanced stage of lung cancer. Regular physical examination, chest X-ray and CT is a good examination method, especially for people with family genetic tendency of lung cancer. Tertiary prevention of lung cancer is clinical prevention or rehabilitation prevention. Its goal is to prevent the deterioration of the disease and prevent the occurrence of disability. Due to the high malignancy and rapid progression of lung cancer, the 5-year relative survival rate is low. For patients with a chance of cure, radical treatment measures are provided. Clinically, a comprehensive approach is mostly adopted to select a reasonable and optimal diagnosis and treatment plan. In clinical practice, we adopt a comprehensive approach and choose the best diagnosis and treatment plan. At the same time, we can restore the local function of the lung and all the functions of the body, promote recovery, improve the quality of life, and even return to society. For patients with no hope of cure, palliative treatment is provided to improve the quality of life and prolong the survival period.