I. Primary prevention of lung cancer As the etiology and risk factors of lung cancer are well studied, including smoking, environmental air pollution, occupational factors and genetic susceptibility, etc., and as lung cancer progresses rapidly and has poor prognosis, there is a lack of effective second-phase preventive measures, primary prevention of lung cancer should be the first priority. As mentioned before, smoking is the main cause of lung cancer. In China, although some places, especially big cities, have implemented legislation to prohibit smoking in public places, it is still very imperfect. Therefore, control of smoking is the primary measure of primary prevention. 2, improve the environment to improve indoor and outdoor air quality is another important means to prevent lung cancer, this aspect requires the participation of the national government departments and the general public throughout society: China’s ecological environment changes to rely on the national government departments to increase ecological environmental protection efforts, in 1991, the State Council promulgated the “Prevention and Control of Air Pollution Implementation Rules”, for the prevention of lung cancer and other related diseases, played an important role. The creation of a small environment must rely on the efforts of the general public themselves, such as strengthening effective ventilation in the living room, the use of air purification devices, the use of environmentally friendly interior decoration materials, cooking with the right choice of oil and the use of fume hoods to prevent inhalation of harmful gases. 3.To carry out labor hygiene and strengthen occupational protection to prevent occupational lung cancer 4.Dietary prevention and chemoprevention of lung cancer chemoprevention aims to prevent and control lung cancer by using drugs, food or nutrients to intervene in precancerous lesions, prevent the occurrence of lung cancer and differentiate and reverse tumor cells. Secondary prevention of lung cancer The primary screening and early diagnosis of lung cancer mainly apply X-ray examination (fluoroscopy, small chest film, frontal and lateral chest film, tomography film, CT film), sputum exfoliative cytology examination, fiberoptic bronchoscopy and so on. Three randomized controlled clinical trials with large samples were conducted in the United States in the 1970s and 1980s to evaluate the role of sputum cytology and X-ray examination in lung cancer screening, and screening of the general population was not advocated because it could not significantly reduce lung cancer mortality, but there is a lack of evidence that these screenings or early diagnosis can reduce lung cancer mortality, so it is not appropriate to conduct large-scale screening in the general population. With the completion of the Human Genome Project and the beginning of proteomic research, many new technologies and methods have emerged, and it has gradually become possible to find ideal tumor markers for screening, early diagnosis, prognosis and guiding individual treatment of common tumors, so as to predict the risk of lung cancer in individuals and provide early diagnosis and treatment for patients. Although there has been great progress in clinical treatment of lung cancer in recent years, the 5-year relative survival rate of lung cancer is still low, generally less than 15%, due to the lack of simple, practical and effective methods for lung cancer patients to make correct diagnosis quickly, and the opportunity for early diagnosis and treatment is lost when waiting for pathological diagnosis, as well as the characteristics of lung cancer itself. Tertiary prevention is to prevent recurrence and metastasis, focus on rehabilitation, palliative and pain management, and provide physical, psychological, nutritional and exercise guidance to improve patients’ survival rate and quality of life through comprehensive and effective treatment. Lung cancer can be prevented, although the mortality rate of lung cancer in China will continue to rise for some time due to the aging of our population and the large population base already exposed to poor lifestyles and environments such as smoking, but as long as we persevere and focus on prevention, we believe we will have a greater effect on the prevention and treatment of lung cancer.