Background: Refractory pneumonia is a special type of pneumonia in children. This study aimed to analyze the effect of bronchoalveolar lavage (BAL) on the clinical efficacy, inflammatory factors, and immune function in the treatment of pediatric refractory pneumonia.Methods: A total of 196 children with refractory pneumonia admitted to our hospital from January 2017 to January 2020 were enrolled and allocated to a study group (n=99) and a control group (n=97). The study group was treated with BAL treatment plus conventional treatment, and the control group was treated with conventional treatment. The clinical efficacy, time of fever regression, time of cough relief, and length of hospital stay were compared between groups. Changes in inflammatory factors, immune function, pulmonary ventilation function, and complications were analyzed. The levels of inflammatory factors in BAL fluid were compared.Results: The times of fever remission, cough relief, and hospital stay of the study group was shorter than those of the control group, and the total clinical effective rate of the study group was higher. At any time after treatment, the levels of interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factoralpha (TNF-α) in the study group were lower than the control group. After 3-day of treatment, IL-6, CRP and TNF-α in BAL fluid in the study group were significantly decreased compared with before treatment.Immunoglobulin A (IgA) and immunoglobulin G (IgG) levels in the study group were higher than those in the control group at any time after treatment, and immunoglobulin M (IgM) levels were lower than in the control group. The levels of oxygenation index (OI), lung dynamic compliance (Cdyn), and work of breathing (WOB) in the study group were higher than those in the control group at any time after treatment.Conclusions: BAL treatment can effectively relieve the inflammatory response, improve immune function and lung ventilation function in children with refractory pneumonia. The clinical effect is remarkable and worthy of promotion.