Objective: To investigate the changes of intestinal flora and injury of intestinal mucosal barrier in rats with immunological liver injury. Methods: The immune liver injury model was established with BCG induction, and the pathological changes of liver tissue of rats were observed. The levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), diamine oxidase (DAO) and D-lactic acid (D-LA) were detected, and the feces were collected for 16S rDNA sequencing analysis of intestinal flora. Results: The diversity of intestinal flora in model group was significantly higher than that in the control group (P＜ 0.05). As to the level of phyla, the dominant bacteria in the two groups both were Firmicutes and Bacteroidetes, which accounted for 59.50 % and 37.90 % in the control group respectively, and 47.92 % and 46.84 % in the model group respectively. Analysis of the difference on the composition of intestinal flora at phylum level showed that the abundance of Firmicutes in model group decreased significantly, and the difference was statistically significant (P＜ 0.05). Compared with the control group, the abundance of Proteobacteria and Actinobacteria increased in the model group, and the difference was statistically significant (P＜0.05). Analysis of the difference on composition of intestinal flora at genus level showed that the abundance of Lactobacillus and Lachnospiraceae in the model group was lower than that in the control group, and the difference was statistically significant (P＜0.05). The abundance of Ruminococcaceae, Alloprevotella, Blautia and Paraprevotella in the model group was higher than that of the control group (P＜0.05). Conclusion: There is excessive growth of intestinal bacteria in rats with acute liver injury induced by BCG, the abundance of Firmicutes and Lactobacillus decreased significantly, the abundance of Proteobacteria and Actinobacteria increased, which leads to the unbalanced structure of intestinal flora and injury of the intestinal barrier.