1.Bronchoscopy: Bronchoscopy technique is the most commonly used method to diagnose lung cancer, including bronchoscopic brush examination, biopsy, needle aspiration and bronchial lavage to obtain cytological and histological diagnosis. The combination of these methods can improve the detection rate. 2. Transbronchial needle aspiration biopsy and ultrasound bronchoscopy-guided transbronchial needle aspiration biopsy (EBUS-TBNA): lymph nodes and masses in the trachea or paratracheal area can be punctured to help diagnose lung cancer and lymph node staging. EBUS-TBNA can be performed in real time for the puncture of intra-thoracic lesions, which can obtain accurate pathological and cytological diagnosis of lung cancer lesions and lymph node metastases, and is more safe and reliable. Transbronchial lung biopsy (TBLB): It can be performed under the guidance of X-ray, CT, airway ultrasound probe, virtual bronchoscopy, electromagnetic navigation bronchoscopy and fine bronchoscopy, and is suitable for the diagnosis of peripheral lung lesions (PPL) in the outer and outer 2/3 of the lung, which is an important tool for non-surgical diagnosis of pulmonary nodules by examining the lumen while diagnosing PPL. 4.Mediastinoscopy: As an effective method to confirm the diagnosis of lung cancer and assess the lymph node stage, it is currently the gold standard for clinical evaluation of the status of mediastinal lymph nodes in lung cancer. 5.Thoracoscopy: It can accurately diagnose and stage lung cancer. For early stage lung cancer that cannot be detected by TBLB and transthoracic lung mass aspiration biopsy (TTNA), especially for small nodular lesions in the lung, thoracoscopic wedge resection of the lesion can achieve clear diagnosis and treatment. For middle and advanced stage lung cancer, thoracoscopic biopsy of lymph nodes, pleura and pericardium, histological and cytological examination of pleural fluid and pericardial effusion can be performed to provide a reliable basis for the formulation of comprehensive treatment plan and individualized treatment plan.