The treatment of left lower lung infection usually includes anti-infective treatment, supportive therapy, and treatment of complications. 1. Anti-infection therapy: left lower lung infection is often caused by bacterial infection, viral infection, mycoplasma infection, etc. Antibiotic drugs (cephalosporin antibiotics, penicillin, etc.), anti-viral drugs (oseltamivir, etc.), anti-mycoplasma drugs (erythromycin, azithromycin) and so on can be used in anti-infection therapy. 2. Supportive therapy: patients with left lower lung infection need to rest in bed, supplement enough protein and vitamins, drink more water, etc. If patients have fever, they can take antipyretic drugs. If the patient has fever, he can take antipyretic drugs, such as ibuprofen capsule, acetaminophen and so on. 3. Treatment of complications: If there are complications of left lower lung infection, such as abscess chest, pericarditis, etc., the complications need to be treated promptly. In the case of pyothorax, in addition to the application of antibiotics, drainage and drainage of pus can be done; in the case of pericarditis, nutritive cardiac drugs can be added, such as fructose 1,6-bisphosphate injection, adenosine triphosphate injection and so on. 4. Others: left lower lung infection should also consider the possibility of tuberculosis infection, and also need to explore the cause of the disease, for example, lung cancer can cause obstructive pneumonia, according to the type of pathology and staging of radiotherapy, surgery and other treatments for the primary disease. The occurrence of left lower lung infection needs to go to the hospital in time for examination and treatment, to clarify the cause of the disease, and not to blindly use medication on their own, in order to avoid delaying the condition.