Many lung cancer patients go to the hospital only after symptoms appear. Before that, because they do not have any discomfort, they think they are healthy and neglect the necessary preventive screening. There is a process of tumor development, and early diagnosis can grasp the first chance of treatment and thus obtain a better prognosis. Adhering to regular physical examination is an important means of early detection of lung cancer. Imaging examination is the key to chest physical examination, including chest fluoroscopy, chest X-ray and chest CT. Chest fluoroscopy is the most economical and can observe the possible lesions dynamically in real time, but the examination results can only be described in words and schematic diagrams, and there is no image data that can be preserved, so no one else can see the real image except the examiner himself, and no before and after comparison in time. The film of chest X-ray can be preserved for a long time, can be read at different times and places, and can be compared with old and new images, so it is the most commonly used examination means in chest physical examination, but due to the overlapping of images of heart, large blood vessels and spine in flat images, it is not effective for observing lesions in some special areas. Chest CT provides us with detailed imaging features in the chest cavity through tomographic reconstruction, and more information can be obtained through computer software for 3D image reconstruction, but it is relatively more expensive. A general physical examination chest X-ray is sufficient, and if suspicious problems are found, further chest CT examinations are performed. Normal people should have a physical examination once a year, and the results of each examination should be saved for before and after comparisons. For lesions suspected of being present, if invasive tests cannot or will not be performed for a definitive diagnosis, imaging review should be performed every 3-6 months to dynamically observe the changes and should not be taken lightly.