The treatment of subpleural ground glass shadow in the lower lobe of the left lung should be decided according to the etiology and pathology of the disease, and cannot be generalized. Subpleural ground glass nodules in the lower lobe of the left lung may be caused by pneumonia, tuberculosis, lung tumors and so on. 1. Pneumonia: mainly caused by bacterial, fungal and viral infections, often accompanied by cough, sputum, fever and other symptoms, the treatment needs to be combined with the results of sputum bacterial culture to select targeted antibiotics, such as bacterial infections should be cephalosporin, penicillin antibiotics, such as cefixime, amoxicillin; fungal infections should be treated with metronidazole, tinidazole, etc. Viral infections should be treated with ribavirin antiviral. 2. Tuberculosis: caused by Mycobacterium tuberculosis infection, often with low fever, night sweats, fatigue and other symptoms, positive antacid staining, the need for appropriate amount, the whole process, combined, long-term, regular application of anti-tuberculosis drugs, including rifampicin, isoniazid, ethambutol, pyrazinamide, streptomycin. 3. Lung tumor: the etiology is unknown, related to abnormality, smoking, radiation, etc. Benign lung tumors, such as less than 5mm, can be temporarily observed and regularly rechecked without special treatment; malignant lung tumors, such as non-small-cell lung cancer, are preferred to be treated with surgery, combined with pathology results to be applied with radiotherapy, immunotherapy, etc. Radiotherapy is preferred to be applied to small-cell lung cancer. The discovery of subpleural ground-glass shadow in the lower lobe of left lung should seek for medical treatment in time to avoid delaying the condition, usually should do a good job in respiratory protection, prohibit smoking, and strengthen one’s nutrition.