Most of the multiple nodules in the lungs are caused by lung infection or tuberculosis, or may be in long-term work contact, inhaled mineral dust particles in the lungs deposited to form dust nodules, can also be seen in pulmonary tuberculosis, rare in lung malignant tumors. 1. Lung infection or tuberculosis causes local lung tissue necrosis, fibrin exudation and granulomatous hyperplasia, if the fibrin is not completely absorbed, the healing of the formation of small fibrous scar foci, the nodule is irregular in shape. 2. Long-term exposure to inhaled dust, minerals and other particles can be deposited in the alveoli to form nodules, commonly found in silicosis and pneumoconiosis. 3. Pathogenic microbial infection, genetic factors, autoimmune and other causes of pulmonary nodular disease, in the lungs, mediastinum appeared in multiple inflammatory granulomas, imaging examination can be manifested as multiple nodules in the lungs. 3. Multiple nodules in the lungs as malignant tumors are relatively rare (1) Metastatic tumor of the lungs: it can manifest as multiple round nodules in both lungs. (2) Primary malignant tumors of the lungs: some of the multiple nodules may show malignant nodal changes such as lobulation and burring, and surgery is generally recommended. For multiple nodules in the lungs, hospital consultation and regular outpatient review are recommended.