Whether CT suspected lung cancer is necessarily lung cancer or not, it needs to be analyzed specifically, CT, as an important imaging tool, has an important guiding role in the diagnosis of lung cancer, which can identify central lung cancer or peripheral lung cancer, especially chest enhancement CT is more conducive to the diagnosis of lung cancer. However, as an imaging diagnostic tool, it cannot diagnose which cytologic classification of lung cancer a patient belongs to. Lung cancer is classified into small cell lung cancer and non-small cell lung cancer according to anatomical classification, and CT as an imaging examination can only determine whether it is central or peripheral lung cancer, and if necessary, it needs to be combined with fiberoptic bronchoscopy to understand the classification of central lung cancer, and if it is peripheral lung cancer, it needs to be given percutaneous lung aspiration cytology to clarify the cell classification. In conclusion, CT can only be used as a clinical diagnosis for suspected lung cancer. If further clarification is needed, it needs to be combined with cytohistological examination to confirm whether it is lung cancer or other benign lung tumors.