Objective To review the characteristics of intestinal microbiome in children with autism spectrum disorder (ASD) based on existing literature evidence, and to explore their correlation with core symptoms of ASD, in order to provide theoretical basis for intestinal microbiome intervention in ASD. Methods The literature on intestinal microbiome characteristics of children with ASD in China was systematically searched for in Wanfang, China national knowledge infrastructure (CNKI), Weipu database (VIP), Web of Science and other relevant databases until January 6, 2024. Qualified articles were selected according to inclusion and exclusion criteria, data were extracted, and the quality of the included articles was evaluated using the Newcastle and Ottawa scale (NOS). Results A total of 33 articles were included, and the study subjects were 2 042 children with ASD aged 2 to 14 years.In 16 studies α or β diversity in the intestinal microbiome was analyzed in the children with ASD and healthy children, of which seven reported α and β diversity, five described only α diversity, and four mentioned only β diversity, but the results were inconsistent.At the phylum level,Firmicutes were the most frequently reported, with 9 articles mentioning that their abundance was related to ASD, followed by Bacteroidetes and Proteobacteria, each mentioned in 7 articles. Megamonas, Megasphaera, Barnesiella, Escherichia, Streptococcus and Bifidobacterium were associated with the severity of ASD. Megamonas, Blautia, Streptococcus, Bacteroides, Clostridium, Sutterella, Lactobacillus and Bifidobacterium were reported to be associated with social behavior, while Megamonas was associated with speech disorders. Bifidobacterium, Streptococcus, Blautia and Bacteroides were associated with cognitive development. Clostridium, Lactobacillus and Bifidobacterium were associated with stereotypical behavior, while Bifidobacterium was associated with mood disorders. The abundance of Firmicutes, Bacteroidetes and Bacteroides was associated with gastrointestinal symptoms such as constipation. Conclusion There are significant differences in intestinal microbiome between children with ASD and healthy children. There is a great number of intestinal microbiome involved in the core and accompanying symptoms of ASD, and most of the microbiome associated with ASD belong to phylum Firmicutes, indicating that the abundance of Firmicutes is closely related to the occurrence and development of ASD.