【Objective】 To evaluate the therapeutic effect of probiotics on core symptoms in patients with autism spectrum disorder (ASD), in order to provide theoretical basis for the treatment and intervention of ASD. 【Method】 Articles published from January 2000 to May 2023 on the effect of probiotics on core symptoms in ASD children were retrieved from 7 databases, including Chinese Biomedical Literature Service System (SinoMed), Wanfang Data Knowledge Service Platform, VIP Citation Database, and China National Knowledge Infrastructure (CNKI), PubMed, Embase, and Web of Science.Meta-analysis was performed using RevMan 5.4.Effect size, combine heterogeneity test sensitivity analysis and subgroup analysis were calculated. 【Result】 Totally 10 studies with 343 patients were included in this Meta-analysis.Meta-analysis showed that there was statistically significant difference in ASD core symptom score between the intervention group and the control group (SMD=-0.34, 95%CI: -0.55 - -0.12, P<0.05).Subgroup analysis showed that the efficacy of the trial conducted in Asian populations was not significant (SMD=-0.32, 95%CI: -0.63 - 0.00, P=0.05).In Caucasian populations, the therapeutic effect was significant (SMD=-0.35, 95%CI: -0.65 - -0.06, P<0.05).Grouped by age, it was found that the efficacy was not significant in trials involving adults (SMD=-0.12, 95%CI: - 0.57 - 0.33, P=0.61), but significant in trials involving only minors (SMD=-0.40, 95%CI: -0.65 - -0.16, P<0.05).According to the treatment course grouping, the intervention for less than 3 months (SMD=-0.35, 95%CI: -0.66 - -0.03, P<0.05) and more than 3 months (SMD=-0.33, 95%CI: -0.62 - -0.03, P<0.05) showed significant therapeutic efficacy.Grouped by bacterial strains, the efficacy of a single microbial community was not significant (SMD=-0.16, 95%CI: -0.46 - 0.15, P>0.05), while the efficacy of a composite microbial community was significant (SMD=-0.51, 95%CI: -0.81 - -0.21, P<0.05). 【Conclusions】 Probiotic therapy is effective in improving the core symptoms of ASD patients, but is influenced by factors such as race, age and probiotic strain. Composite microbiota has better efficacy in Caucasian and underage populations.