People often find occupying lesions in the lungs during physical examination or chest examination for other conditions, ranging from the size of a bean to half of the chest cavity, and sometimes benign and malignant cannot be well identified, causing a lot of trouble and fear for patients and their families. Isolated lesions can be formed in the lung for various reasons, and the common ones are as follows: peripheral lung cancer, pulmonary adenoma, pulmonary smooth muscle tumor, pulmonary malformation tumor, multiple pulmonary metastases, pulmonary tuberculosis ball, pulmonary inflammatory pseudotumor, spherical pneumonia, pulmonary abscess, pulmonary fluid-containing cyst, pulmonary cysticercosis, pulmonary artery aneurysm, and traumatic hematoma. To determine the nature of the lesion is quite important for the choice of treatment plan, the identification of the nature of the mass must be combined with X-ray and clinical manifestations and necessary laboratory tests, sometimes it is necessary to perform mass puncture, and different puncture methods should be used for different lesion locations. A retrospective analysis of 511 patients with pulmonary masses was performed on the method of percutaneous lung puncture, puncture rate, positive rate and complications. The results showed that 546 punctures were performed in 511 cases, of which 371 were performed under fluoroscopic guidance with a puncture rate of 92.9%. 195 punctures were performed under CT guidance with a puncture rate of 100%. The correct biopsy rate was 90.8%. The biopsies near the hilum can be taken by fiberoptic bronchoscopy and magnified to a certain magnification for cytological examination under the microscope, and in individual cases, the pathology department can perform firm examination at the molecular level (e.g. immunohistochemistry). New MRI techniques also play a considerable role in the diagnosis of lung occupancies. x-ray examinations are essential, including plain CT, spiral CT 3D imaging techniques, CT-guided puncture techniques, etc. PET is a kind of positron emission computed tomography, which is a good test to identify benign and malignant tumors. It is also more expensive. Through these examinations, valuable information can be found to help clinicians make diagnosis and proper treatment plan. Some lesions are difficult to determine benign and malignant for a while, and need dynamic observation for a period of time, or observation of lesion changes after treatment. Sometimes it is necessary to obtain the lesion during surgery after opening the chest and perform rapid pathological examination, and the exact diagnosis of the lesion can usually be completed after half an hour, and the decision on the operating table is made to remove the lesion scope and whether to clear the lymph nodes. Pulmonary lesions up to 2 cm in diameter are necessary for surgical exploration and resection if they cannot be judged as benign or malignant, because, the surgical cure rate of early peripheral lung cancer is high and easy to operate. At present, because of the minimally invasive thoracoscopic technology, peripheral lung lesions with a diameter of 0.5 cm or more can also be operated. The general statistics show that the chance of lung cancer being operated after detection is only 15%, which means that 85% of lung cancer has lost the chance of surgery, indicating that lung cancer is insidious and not easily detected, so chest fluoroscopy is a necessary examination during health checkups. Smokers with a long history of smoking should be more alert.