The diversity of intestinal flora in ruminants plays an important role in the quality of animal meat. In this study， high-throughput sequencing was used to analyze the effects of Lactobacillus on intestinal flora composition and meat quality of Sunit sheep. Twelve 3-month-old healthy Sunit sheep were divided into two groups， one group was fed with basic diet， the other group was fed with 0.5% Lactobacillus and slaughtered after 90 days. The results showed that Bacteroidetes and Verrucomicrobia in the intestinal flora of the Lactobacillus group were significantly higher than the control group (P<0.05)， Lachnospiraceae NK3A20 group and Alistipes were significantly lower than the control group (P<0.05). In the Lactobacillus group， the redness value a* and luminance value L* were significantly higher than the control group (P<0.05)， the flavor substances such as hydrocarbons， ketones and esters were significantly higher than the control group (P<0.05)， the contents of amino acids and unsaturated fatty acids were significantly higher than the control group (P<0.05)， and the shear force was significantly lower than the control group (P<0.05). Lactobacillus added to feed could optimize intestinal flora composition of Sunit sheep， promote nutrient metabolism of the body and improve meat quality.