To investigate the effects of distillers’ grains(DG) on reproductive performance and colostrum composition of sows in late pregnancy, a total of 72 healthy PIC sows(80 days of pregnancy) were randomly divided into two groups, with 6 replicates in each group and 6 sows in each replicate. The control group was fed a basal diet, and the DG group was supplemented with 1%(mass fraction) Fuyu flavor DG in the basal diet. The experimental period was from 80 days of pregnancy to delivery. The results showed that the litter weight, number of live piglets and number of healthy piglets in the DG group were significantly higher than those of the control group(P<0.05), while the number of intrauterine growth retardation(IUGR) piglets was significantly decreased(P<0.05). DG decreased the mass concentration of urea nitrogen in colostrum of sows(P<0.05), but there was no significant difference in immunoglobulin(IgA, IgG, IgM) mass concentrations(P>0.05). DG increased the molar concentrations of serum triglyceride(TG) significantly(P<0.05). The serum cholesterol(TC) and high-density lipoprotein(HDL-C) concentrations, along with the total superoxide dismutase(T-SOD) and catalase(CAT) activity, and glutathione peroxidase(GSH-Px) activity in placental tissue exhibited highly significant elevations(P<0.01), but the molar concentration of interleukin-2(IL-2) was significantly decreased(P<0.05) in the DG group. DG had no significant effect on the intestinal microflora clustering, Chao1 index, observed_species, PD_whole_tree and Shannon index(P>0.05). However, DG reduced the relative abundance of Spirochaetota(P<0.01) and Treponema(P<0.05), and increased the relative abundance of Clostridiaceae(P<0.05). In summary, supplementation of 1% DG in the diet of sows during late pregnancy can effectively improve the reproductive performance and antioxidant capacity, alleviate inflammation and affect the gut microbiota structure of sows.