The treatment of left interlobular pleural thickening includes drug treatment, surgical treatment, functional exercise, etc., and the use of drugs should follow the doctor’s instructions. Left interlobular pleural thickening is described as an abnormality seen on chest imaging, with thickening of the obliquely cleft or horizontally cleft interstices seen on CT, and can be caused by pleural inflammation, such as pleurisy, or by non-inflammatory lesions, such as tumors. Most interlobar pleural thickening is benign and old and does not require special management. If it is combined with cough, fever, pleural effusion, etc., it requires pleural fluid extraction, use of sensitive antibiotics, such as cefuroxime, etc., and use of cough suppressants, such as dextromethorphan, etc., if the cough symptoms are severe. In case of tuberculous pleurisy, anti-tuberculous drugs such as streptomycin and rifampicin should be used in combination. If it is caused by tumor, it should actively treat the original disease, radiotherapy, etc., chemotherapy drugs such as cisplatin. Pleural thickening is serious, affecting the lung function, can consider surgical treatment, such as peeling off the thickened fibrous plate. Simple interlobar pleural thickening can usually strengthen the respiratory function exercise, such as moderate running, swimming, etc. to improve lung function. Left interlobular pleural thickening, it is recommended that patients go to the regular hospital in time to avoid delaying the condition. Drugs need to be used under the guidance of a doctor, avoid self-medication.