Severe pulmonary infections are all severe pneumonia with late onset and multiple drug-resistant risk factors. The length of life of patients with severe lung infections is related to the patient’s age, the presence of underlying disease, the causative organisms of the infection and drug resistance, etc. If the infection is well controlled, it does not have much impact on life expectancy. The common causative agents of severe lung infections are Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Bacillus immobilis, Enterobacter spp. bacteria, and anaerobic bacteria. These bacteria are highly susceptible to drug resistance and require the selection of broad-spectrum antibiotics to cover all possible causative organisms at adequate doses. After the bacterial culture results identify the causative organisms, the step-down and targeted selection of narrow-spectrum antibiotic therapy is timely. For severe pulmonary infections caused by multi-drug resistant Pseudomonas aeruginosa and immobile bacilli, quinolones or aminoglycosides combined with carbapenem antibiotics can be used. If clinical symptoms improve 48 to 72 hours after the administration of these treatments, the prognosis will be good if anti-inflammatory therapy is effective and the infection is well controlled, with no impact on survival time. If control is poor, sepsis will develop quickly, which in turn will lead to infectious shock, and life expectancy will not exceed one week.