〔Abstract〕 Objective To analyze the efficacy of bilevel positive airway pressure ventilatior (BIPAP) assisted bronchoalveolar lavage in severe pneumonia patients with respiratory failure in the intensive care unit (ICU). Methods A retrospective analysis was conducted on the clinical data of 98 ICU patients with severe pneumonia and respiratory failure admitted to Putian University Affiliated Hospital from April 2021 to April 2023. They were divided into a control group and an observation group according to different treatment measures. Among them, 47 patients who received BIPAP alone were included in the control group, while 51 patients who received BIPAP assisted bronchoalveolar lavage treatment were included in the observation group, all of whom continued treatment for one week. Compare the clinical efficacy, respiratory function indicators, blood gas analysis indicators, and inflammatory factor levels between two groups of patients. Results The clinical treatment efficiency of the observation group was higher than that of the control group, and the difference was statistically significant (P < 0.05). After treatment, the respiratory rate, oxygenation index, and dynamic compliance of the observation group were better than those of the control group, with statistically significant differences (P < 0.05). After treatment, the arterial partial pressure of oxygen (PaO2) of the observation group was higher than that of the control group, and the arterial partial pressure of carbon dioxide (PaCO2) was lower than that of the control group, with statistically significant differences (P < 0.05). After treatment, the levels of serum C-reactive protein (CRP), procalcitonin (PCT), and white blood cell (WBC) count in the observation group were lower than those in the control group, with statistically significant differences (P < 0.05). Conclusion BIPAP assisted bronchoalveolar lavage has a significant therapeutic effect on ICU patients with severe pneumonia combined with respiratory failure. It can reduce the inflammatory response of the patient's body, improve respiratory function and blood gas analysis indicators, promote clinical symptom resolution, and has certain application value.