Background: People living in plateau areas are prone to upper respiratory tract infections and secondary lung infections. The current study aimed to explore the effects of bronchoalveolar lavage under fiberoptic bronchoscope for the treatment of patients with severe pulmonary infection living in plateau areas.Methods: 148 patients with severe lung infection admitted to the intensive care unit of Shigatse People's Hospital (Shigatse, Tibet Autonomous Region, China) between July 2019 and January 2021 were enrolled.Patients were randomly assigned to the observational group or the control group. For all patients, basic clinical data including sex, age, body mass index (BMI), blood pressure, diabetes history, stroke history, presence or absence of chronic obstructive pulmonary disease, lung infection (gram-positive bacterial infection, gram-negative bacterial infection, fungal infection, acute lung abscess), surgical history, and postoperative inhalation injury. were collected. The control group received conventional treatment, and the observational group received bronchoalveolar lavage under fiberoptic bronchoscopy. Pearson's correlation was used to analyze the correlations between bronchoalveolar lavage under fiberoptic bronchoscopy and inflammatory factors levels. Logistic regression was used to investigate the correlation between bronchoalveolar lavage under fiberoptic bronchoscopy and the effectiveness of the treatment.Results: Before treatment, no significant difference existed in the basic data of the observational group and the control group. After treatment, the parameters of respiratory mechanics and inflammatory factors in the 2 groups were significantly improved compared with those before treatment (P<0.05). At the same time, in the observational group, the clinical parameters were significantly higher than those of the control group, and the levels of inflammatory factors were significantly lower than those of the control group (all P<0.05).After full adjustment for age, sex, BMI, gram-negative infection, diabetes, and acute lung abscess, compared with the control group, the therapeutic effectiveness in the observational group was increased by 23% (OR =1.23, 95% CI: 1.09-1.51, P=0.007).Conclusions: For patients with severe lung infection who are resident in high altitude areas, compared with conventional treatments, bronchoalveolar lavage under fiberoptic bronchoscopy can significantly improve chest, lung, and total dynamic compliance, as well as reduce the levels of the inflammatory factors procalcitonin (PCT) and transforming growth factor-β, thus increasing the effectiveness of the treatment.