Lung space-occupying lesions are abnormal neoplastic lesions on imaging of the lungs, including benign and malignant tumors of the lungs, inflammation, silicosis nodules, and parasites. For patients who are initially examined by chest radiographs or chest CT, the abnormal neoplastic lesions in the lungs seen on imaging cannot be diagnosed by imaging alone, so they are generally referred to as pulmonary space-occupying lesions. Rather, after careful examination as well as symptomatic treatment, it is often no longer possible to make a final diagnosis of a pulmonary space-occupying lesion. Clinically, there are many different types of lung-occupying lesions, the more common being inflammatory tissue in the lungs, silicosis nodules, calcified foci, benign and malignant tumors, and parasites. A medical history is needed, such as asking about cough, sputum, coughing up blood, fever, weight loss, and fatigue. Combined with the tumor markers of lung cancer, as well as routine blood tests, chest enhanced CT, and puncture biopsy of the tumor, the nature of lung space-occupying lesions can be comprehensively determined.