〔Abstract〕 Objective To study the clinical effect of inhaled acetylcysteine combined with budesonide in the treatment of children with bronchopneumonia. Methods A total of 370 children with bronchopneumonia admitted to Xiamen Haicang Hospital from March 2019 to March 2021 were selected and divided into control group and observation group by random number table method, with 185 cases in each group. The control group was treated with 0.9% sodium chloride injection + budesonide atomization inhalation, and the observation group was treated with acetyl-cysteine inhalation on the basis of the control group. The efficacy of the two groups was compared. Results The total effective rate in the observation group was 92.43% higher than that in the control group (71.35%), the time of clinical symptoms disappearing in the observation group was significantly shorter than that in the control group, and the incidence of adverse reactions in the observation group was 3.24%, lower than that in the control group (9.73%), with statistically significant differences (P < 0.05). After treatment, the levels of IgA, IgG and IgM in the observation group were higher than those in the control group, the differences were statistically significant (P < 0.05). Conclusion Inhalation acetyl cysteine + budesonide atomization inhalation is effective in the treatment of bronchopneumonia, which can improve the total effective rate, shorten the time of clinical symptoms, improve the level of immune function, and has high safety, better than the use of budesonide alone.