1.Chest X-ray: Chest X-ray is the first choice method to check lung cancer, which can detect lung lesions of 0.6-0.8 cm or more. The sensitivity of chest X-ray for lung cancer is about 80%. It is difficult to detect lesions in hidden areas, such as around the heart and hilar region of lung. 2.CT of chest: It can detect lesions in hidden parts of lung that cannot be detected by X-ray chest radiography, and can show the shape, size, lobularity and degree of invasion of lesions, and also determine whether there are lymph node metastases and determine the clinical stage of lung cancer. 3.Sputum cytology examination: the first sputum after the patient wakes up early in the morning is sent for examination more than 3 times. The positive detection rate can reach 70% to 80%. 4. Fiber or electronic bronchoscopy: generally not used for early screening of lung cancer, but for high-risk groups, especially those with moderate or severe atypical hyperplasia detected by sputum cytology and negative X-ray examination, bronchoscopy should be performed. 4.PET-CT imaging: positron emission computed tomography (PET) is one of the most promising imaging techniques, with high sensitivity, specificity and accuracy for single nodules in the lung. 5.Fiber bronchoscopy: It can clarify the degree of airway infiltration and the nature of the lesion, but it cannot examine the peripheral lung lesions. 6.Oncology index examination. 7.Pulmonary tumor puncture biopsy. 8, Thoracoscopic lung lesion biopsy, resection.