Occupancy of the lungs refers to an abnormal structure in the lungs found on imaging, the nature of which is undetermined and requires further diagnosis and treatment. Lung occupancy refers to the presence of a shadow larger than 3 cm on imaging (including chest radiographs, CT, and ultrasound) of undetermined nature, which may be a lung tumor, tuberculosis ball, hematoma, or parasite. If a space-occupying lesion in the chest is found, its nature should be further clarified, such as by fiberoptic bronchoscopy biopsy or surgical rapid frozen section. After further examination, appropriate treatment should be carried out according to the diagnosis. In case of lung cancer, elective surgery with intraoperative lymph node dissection and postoperative radiotherapy should be performed. In case of tuberculosis ball, regular anti-tuberculosis treatment is required. There are other causes of occupational lesions in the lungs, and patients are advised to seek timely medical treatment, identify the causes and treat them actively.