The main role of low-dose CT is to perform lung cancer screening. Low-dose CT refers to the reduction of normal CT radiation without affecting the examination effect, so as to minimize the damage of CT radiation to the human body, and currently low-dose CT of the chest is considered to be a powerful tool for lung cancer physical examination and screening. Chest low-dose CT is suitable for regular physical examination, high-risk group screening, lung cancer screening, and for high-risk groups who are ≥40 years old, long-term smokers; have a history of environmental or high-risk occupational exposure such as asbestos; have a history of lung diseases such as chronic obstructive pulmonary disease (COPD), diffuse pulmonary fibrosis (DPLF), or a history of tuberculosis (TB); or have a history of malignant tumors or a family history of lung cancer. Annual screening with low-dose CT of the chest is recommended.