The experiment aimed to investigate the effects of dietary supplementation with Bacillus subtilis QST 713 (BS) on the reproductive performance, perinatal constipation, and offspring growth performance of sows. 78 multiparous Landrace-Yorkshire sows with same parity and backfat thickness were divided into 2 groups: a basal diet group (CON) and a basal diet supplemented with 1.5 x 10(9) CFU/kg BS. The experiment was conducted from day 85 of gestation to day 21 of lactation. Reproductive performance, lactation performance, and perinatal fecal scores of sows were recorded. Samples were collected for subsequent analysis, including the feces of sows on day 110 of gestation, colostrum within 2 hours of parturition, milk on day 21 of lactation and feces from sows on day 21 of lactation. The results showed that, compared with the CON group, the BS group significantly shortened the duration of parturition (P < 0.01) and the average birth interval of piglets (P < 0.05), reduced stillbirth rate (P < 0.05) and invalid piglet rate (P < 0.05). Additionally, the BS group increased the content of protein (P < 0.05) and level of IgM in colostrum (P < 0.05), as well as the average daily gain (P < 0.05) of weaned piglets. The BS group increased the perinatal fecal score (P < 0.05) of sows, decreased the incidence of post-partum constipation (P < 0.05), and increased the relative abundance of Lactobacillus (P < 0.05) in feces on day 110 of gestation. In summary, a maternal diet supplemented with BS reduced the stillbirth rate by shortening the duration of parturition, alleviated perinatal constipation, and improved intestinal microbiota, meanwhile improving the growth performance of piglets by increasing nutrients and immunoglobulins in colostrum.