Objective To systematically evaluate the efficacy and safety of Bifidobacteria in preventing caries. Methods Databases including PubMed, Embase, The Cochrane Library, Web of Science, Scopus, Clinicaltrials. gov, CNKI, WanFang Data and VIP were electronically searched from inception to April 2020 to collect randomized controlled trials of Bifidobacterium for caries. Meta-analysis was performed using Revman 5.4 software. Results In total, 10 randomized controlled trials (RCT) of 518 patients, including 262 in the test group and 256 in the control group, were included. Meta-analysis results reveal no statistically significant differences in salivary Streptococcus mutans counts (SMD=-0.31, 95%CI -0.66 to 0.04, P=0.08) (RR=0.53, 95%CI 0.17 to 1.66, P=0.28) and salivary Lactobacilli counts (SMD=-0.07, 95%CI -0.39 to 0.26, P=0.69) (RR=0.87, 95%CI 0.59 to 1.29, P=0.50). No statistical differences in the counts of Streptococcus mutans and Lactobacillus counts were noted in dental plaque, and no statistical difference in the occurrence of caries in deciduous teeth. Three of the 10 RCTS included in this study did not report adverse events, 5 had no adverse reactions, and 2 reported gastrointestinal discomfort.Conclusion Current evidence suggests that Bifidobacteria do not effectively reduce Streptococcus mutans counts and Lactobacillus counts in saliva and dental plaque, or reduce the occurrence of caries in deciduous teeth. The safety of this treatment also requires further investigation.