Lung cancer is the malignant tumor with the highest morbidity and mortality rate, which are very close to each other. Although the efficacy of comprehensive treatment for lung cancer has been improved, the treatment for advanced lung cancer is still unsatisfactory. There is no doubt that early detection and early treatment of lung cancer are very important to prolong the survival of patients, and the 5-year survival rate of patients can reach about 70% with early surgical treatment, while the 5-year survival rate of patients with advanced lung cancer treatment is only about 5%. Screening is a regular preventive examination for asymptomatic people with the aim of detecting tumors when they appear asymptomatic. Research began in the 1950s, and several clinical trials have been conducted since then using plain chest radiographs, sputum cytology, and later chest CT technology, but none of them have found that screening reduces lung cancer mortality. The National Lung Screening Trial NSLT was published in 2011 and finally a consensus was reached on this issue. Screening for lung cancer using low-dose CT (LDCT) for 3 years in a high-risk group reduced lung cancer mortality by 20% and all-cause mortality by 6.7% compared to 3 years of chest radiographs. Therefore, in February 2012, the National Comprehensive Cancer Research Network (NCCN) issued guidelines for lung cancer screening, making such screening an effective method for preventing and controlling lung cancer. The low-dose CT scan (LDCT) technique is used to obtain low-resolution images under the condition of low radiation exposure with a single breath-hold, and has a high sensitivity for nodules with a maximum diameter of 2 to 3 mm. Low-dose spiral CT (LDCT) is used to screen mainly for people at high risk of lung cancer, including those aged >55 years with a smoking index of ≥30 pack-years; those who are smoking or have quit smoking for <15 years; those aged ≥50 years while smoking for ≥20 pack-years and have a risk factor, giving at least 1 LDCT of the chest once every 12 months to detect and observe the status of lung lesions, and when the lesions may be at increased risk of The radiation value of LDCT is 1/5 of that of regular CT and only 1.5 times that of regular chest radiographs, and there were no results of increased mortality in the NSLT study, thus proving its safety.