Lung cancer is a common malignant tumor of respiratory system, and lung cancer patients will have dyspnea, which is also one of the common clinical manifestations of advanced lung cancer patients. The causes of dyspnea in lung cancer are as follows: 1) Cancer tissues can cause compression or obstruction of trachea and bronchial tubes, thus causing dyspnea; 2) Pleural metastasis of lesions can cause pleural effusion, and a large amount of pleural effusion compression can also cause dyspnea in patients. After the clinical manifestation of dyspnea, in addition to anti-tumor treatment, we can also give local thoracic puncture tube drainage of pleural fluid, thoracic cavity injection of cisplatin and other anti-tumor drugs to inhibit the production of pleural fluid, reduce pleural fluid to improve pleural effusion, reduce the clinical manifestation of dyspnea.