Objective To systematically evaluate the effect of sub-hypothermia intervention on children with severe brain injury. Methods Computer-based search was conducted in such databases or websites as Chinese National Knowledge Infrastructure (CNKI), SinoMed, Wanfang Data, PubMed, Web of Science, etc., to find relevant RCTs. Rev Man 5.3 and Stata 15.0 were used for Meta-analysis. Results A total of 924 children were included in 14 RCTs. Meta-analysis showed that there were no significant differences in mortality and Glasgow Outcome Scale （GOS） scores between sub-hypothermia and normal temperature groups (P>0.05 for all). Sub-hypothermia played some role in early reduction of intracranial pressure (ICP) in children. Compared with normal temperature group, sub-hypothermia group significantly increased the incidence rate of arrhythmia (P<0.05). The differences in the incidence rates of other complications (as in infection, bleeding, coagulation dysfunction, pneumonia, ARDS, and septic shock )between sub-hypothermia and normal temperature group were not significant (P>0.05 for all). Conclusion Although hypothermia has some effect on brain injury, its application in temperature management in children with brain injury should be cautiously considered.