Objective To investigate the efficacy and safety of belizumab in the treatment of children with systemic lupus erythematosus (SLE). Methods The clinical data of SLE children who completed 28-week treatment with beliumab from January 1, 2020 to December 31, 2021 were retrospectively analyzed. Results A total of 17 children (5 boys and 12 girls) were enrolled, and the average age was (12.1±2.3) years. The median disease duration from onset to targeted drug therapy was 5.0 (1.0-22.0) months. Compared with the pre-treatment group, the proportion of rash, fever, lupus nephritis and blood system damage decreased, the CD3⁺ and CD4⁺ cell counts increased, the CD19⁺ cell counts decreased, the positive rate of anti-ds-DNA decreased, and the dosage of glucocorticoids decreased in the post-treatment group, and the differences were statistically significant (P<0.05). There was significant difference in the systemic lupus erythematosus disease activity index (SLEDAI-2000) at different time points (weeks 0, 2, 4, 8, 12, 16, 20, 24 and 28) after beliumab treatment (P<0.01), and the score showed a downward trend. Among the 17 SLE children, 5 (29.4%) achieved lupus low disease activity state (LLDAS) and 3 (17.6%) achieved clinical remission by the end of observation (week 28). There was no complication of serious infection and no allergic reaction to belizumab. Conclusions Beliumab combined with traditional drugs in the treatment of SLE may help children more easily achieve LLDAS and clinical remission without severe adverse effects.