Objective To explore the effects of sialic acid intervention during pregnancy and the lactational period on the intestinal function of autism model rats. Methods Thirty SPF-grade adult male and female Wistar rats were mated. The successfully pregnant rats were randomly assigned to a valproate-induced model (VPA) group, a high-dose sialic acid (SAH)group, a medium-dose sialic acid (SAM) group, a low-dose sialic acid (SAL) group, and a control (CON)group (n=6 per group) and were housed individually in single cages. On the 12. 5th day of pregnancy(E12. 5), rats in the VPA and SA intervention groups were given a single intraperitoneal injection of 600mg / kg sodium valproate (VPA), while the pregnant rats in the CON group were given an equal amount of normal saline. The SA intervention period was from E12. 5 to the 21st day after parturition. Feces of offspring rats in each group were collected. The diversity and structure of the gut microbiota were detected by 16S rRNA sequencing. The intestinal transit speed in each group was detected by intragastric administration of carmine. The levels of intestinalrelated neurotransmitters ( substance P, enkephalin, 5-hydroxytryptamine, vasoactive intestinal peptide, and glutamate, gamma-aminobutyric acid) in the blood of rats in each group were detected by ELISA. Results Highdose SA intervention did not affect the diversity of the gut microbiota in the VPA-induced autism model rats, but it changed the structure of the gut microbiota and increased the abundance levels of Prevotella _ NK3B31 group,Prevotella, Prevotella spp. , Alloprevotella, Lachnospira, Ruminococcus, and Bacteroides (P<0. 05). High-dose SA also promoted the intestinal transit speed, and increased the levels of vasoactive intestinal peptide, 5-hydroxytryptamine, and gamma-aminobutyric acid in serum. Conclusions SA intervention during pregnancy and the lactational period affects the intestinal transit speed of VPA-induced autism model rats, changes the structure of the gut microbiome, and increases the levels of vasoactive intestinal peptide, 5-hydroxytryptamine, and gammaaminobutyric acid.