Abstract：Objective To investigate the clinical effect of meropenem in the treatment of children with severe pneumonia. Methods A total of 80 children admitted to our hospital and diagnosed with severe pneumonia from January 2020 to January 2022 were selected and randomly divided into a control group and an observation group, with 40 children in each group. The control group was treated with cefoperazone sulbactam，while the observation group received a combination of cefoperazone sulbactam and meropenem. The clinical efficacy, levels of serum procalcitonin （PCT）, interleukin-13 （IL-13）, lipid peroxidation （LPO）, superoxide dismutase （SOD）, and blood gas analysis indicators were compared between the two groups.Results The effective rate of treatment in the observation group was higher than that in the control group, with a statistically significant difference （χ2＝7.813, P＜0.05）. After treatment, the levels of PCT, IL-13, and LPO in the observation group were lower, while the level of SOD was higher compared to the control group, with significant differences （t＝8.729, 10.766, 11.695, 8.780, all P＜0.05）. The levels of arterial oxygen pressure （PaO2） and arterial oxygen saturation （SaO2） in the observation group were higher, and the level of arterial carbon dioxide pressure （PaCO2） was lower than that in the control group, with significant differences （t＝7.783, 6.340, 9.506, all P＜0.05）.  Conclusion The combined treatment of cefoperazone sulbactam and meropenem in children with severe pneumonia can effectively improve the clinical condition and related biomarkers of children with severe pneumonia.