Dry cough is not a specific symptom of lung cancer, but when some coughs are combined with hemoptysis, it is necessary to go to the respiratory department of a hospital for relevant examinations in a timely manner. Dry cough can be caused by many diseases, such as mycoplasma pneumonia, viral pneumonia, tuberculosis infection, lung cancer, bronchial foreign body, etc. Therefore, dry cough is not a specific symptom of lung cancer, but needs to be combined with other symptoms for comprehensive diagnosis. If patients have dry cough for a long time and symptoms such as hemoptysis, fever, chest pain, weight loss, etc., they need to visit the respiratory department of hospital and can arrange CT examination. If nodular foci in the lung are found, showing solid mixed ground glass shadow with burr and vacuolation sign, and enhancement can be seen, lung cancer can be diagnosed. To further clarify the cause, fine needle aspiration studies are required and treatment is guided according to the results. It is recommended that patients with prolonged dry cough need to visit the respiratory department of the hospital in time to avoid delaying the disease.