Lung cancer is currently the tumor with the highest cancer mortality rate. The treatment method for lung cancer with a high cure rate is early surgery, and early screening of lung cancer can improve the survival rate of lung cancer. However, according to the current conventional diagnosis and management methods, lung cancer still has an extremely high morbidity and mortality rate. Therefore, finding effective early screening methods for lung cancer is one of the goals that medical practitioners have been striving for in the past 50 years. At present, early screening for lung cancer is still mainly focused on imaging and morphological methods. In this paper, we synthesize and summarize some international early screening programs for lung cancer, which are studied through evidence-based medical methods to reach conclusions. As far as possible, different screening methods are analyzed and evaluated by using randomized studies. I. Plain chest X-ray (CXR) CXR screening was initially based on the monitoring of patients with intermediate to advanced lung cancer who were symptomatic. In contrast, CXR is often less effective in detecting stage I patients with small asymptomatic nodules. Early lung cancer is cured by lobectomy of the lung cancer site, and the screening efficiency can be assessed by the detection rate of CXR for early lung cancer. The theoretical basis of sputum exfoliative cytology is to diagnose lung cancer while cancerous cells are observed in certain individuals. As the most common histopathological type of lung cancer migrates from squamous to adenocarcinoma, sputum exfoliation cytology will gradually lose its value as a screening tool in the sense of epidemiological studies. III. Low-dose CT scan (LDCT) Low-dose CT scan (LDCT) technique is to obtain low-resolution images under the condition of low radiation exposure with a single breath-hold, and this test has a high sensitivity for nodules with a maximum diameter of 2~3 mm. In addition, three-dimensional images can be reconstructed by LDCT and standard CT scans to evaluate the basis of nodule growth in a continuous manner. The theoretical basis of LDCT is an improvement and development of an early detection technique, mainly in two aspects: 1. the ability to detect smaller nodules; 2. the shape and growth pattern of nodules can be obtained by invasive diagnostic tests. Currently we expect to enhance both: 1. increase the proportion of early stages of lung cancer detected; and 2. reduce the number of increased procedures required by patients after abnormalities are detected.