The examination methods of early lung cancer are as follows: 1. Chest CT examination, chest CT is the most important means to diagnose lung cancer, and it can indicate the location and extent of lesion involvement, and provide important reference opinions to distinguish benign and malignant. Low-dose spiral chest CT can effectively detect early lung cancer. When lung cancer is highly suspected or clearly diagnosed, enhanced CT chest examination is needed; 2. CT-guided percutaneous lung lesion aspiration biopsy is an important diagnostic technique to obtain cytology and histology; 3. autofluorescence bronchoscopy, which is of great value for the diagnosis of early centralized type lung cancer, can increase the early malignancy detection rate.