Type 1 diabetes mellitus（T1DM）is an autoimmune disease characterized by the destruction of islet beta cells in the pancreas triggered by genetic and environmental factors. Over the past few decades，extensive familial and genome⁃wide association studies have revealed more than 50 risk loci in the genome. However，genetic susceptibility cannot fully explain the global increase in T1DM incidence，most likely due to the increasing influ⁃ ence of environmental factors，especially the gut microbiota. Recently，evidence from human subjects and animal models has revealed that the gut microbiota as an environmental factor is involved and plays an important role in the pathogenesis of T1DM. However，there are few studies on the analysis of the gut microbiota in children with T1DM. This article reviews the research progress of gut microbiota and T1DM.