CT is not able to detect lung cancer definitively. If CT finds smaller lesions in the lungs, pathologic examination should be further improved to confirm the diagnosis. CT can find nodules and other occupying lesions in the lungs, and can clarify the size, density, and growth of the lesions. It can roughly distinguish between benign and malignant tumors, but not a definitive diagnosis. Once occupying lesions are found in the lungs after CT examination, in order to avoid misdiagnosis, endoscopic examination such as bronchoscopy should be further perfected, and the lesion tissues should be taken and biopsied through pathology to clarify whether they are malignant tumors and the tumor typing. It is recommended that the patient actively cooperate with the doctor to improve the relevant examination, to clarify the diagnosis in time and take targeted measures.