OBJECTIVE; To systematically evaluate the efficacy and safety of omalizumab in the treatment of children with moderate-to-severe allergic asthma. METHODS; CNKI, Wanfang Data, PubMed, Cochrane Controlled Register of Trials ( CENTRAL) and Embase database were retrieved to collect the randomized controlled trial of omalizumab in the treatment of children with moderate-to-severe allergic asthma ( the study group was treated with omalizumab, while the control group received other drugs or placebos for the treatment of allergic asthma). The retrieval time was from the establishment of the database to Mar. 2021. Two reviewers screened the literature and extracted data according to the inclusion and exclusion criteria, Meta-analysis was performed by using RevMan 5. 4 software. RESULTS: Totally 8 randomized controlled trials were collected, including 1 756 children. Meta-analysis results showed that the incidence of asthma exacerbation( exacerbation incidence expressed as number of person-days at risk of exacerbation; RR= 0. 68,95%Cl = 0. 55-0. 85, P = 0. 000 7; exacerbation incidence expressed as percentage of children with exacerbation; RR = 0. 54,95%C/= 0. 45-0. 66, P<0. 000 01) in the study group was significantly lower than those in the control group, and the excellent rate of Global Evaluation of Asthma Effectiveness (GETE) (RR = 1. 39, 95%CI= 1. 23-1. 58, P<0. 000 01), Children' s Asthma Control Test (C-ACT) score (MD = 0. 76, 95% C/ = 0. 31-1. 21, P= 0. 001) were significantly higher than those in the control group, and the differences were statistically significant. The difference of percentage of forced expiratory volume in one second to estimated value (FEV,%) (MD= 0. 62,95%C/=-0. 89-2. 13, P= 0.42), and the forced expiratory volume in the first second to the forced vital capacity (FEV/FVC) (MD = —0. 10, 95%CI= —0. 98-0. 79, P= 0. 83) was not statistically significant. The incidence of severe adverse events in the study group was significantly lower than that in the control group ( RR = 0. 54,95% CI = 0. 39-0.76, P=0.000 4), and time of absence from school ( MD = — 0. 30, 95% C/ = — 0.57-- 0. 02, P = 0. 04 ) was significantly shorter than the control group, the differences was statistically significant. CONCLUSIONS: Omalizumab can effectively improve the clinical indicators of children with moderate-to-severe allergic asthma, significantly reduce the incidence of severe adverse events, and improve the quality of life of children. [ABSTRACT FROM AUTHOR]