Previous research has shown that microbes play a role in immune-related diseases. Our study reveals that children with Henoch-Schönlein purpura nephritis have distinct and altered tongue coating microbiota, characterized by significant changes in species richness, diversity, and specific microbial compositions compared with healthy controls. Nevertheless, the particular involvement of tongue coating microbiota in Henoch-Schönlein Purpura remains unclear. A total of 26 children were enrolled, including 13 patients with HSP and 13 healthy children. Tongue coating samples were collected for DNA extraction and 16S rRNA gene sequencing. Alpha diversity indices, including ACE, Chao1, Shannon, and Simpson indices, revealed significantly lower richness and diversity of tongue coating microbiota in children with Henoch-Schönlein purpura compared to healthy controls. Beta diversity analysis demonstrated distinct clustering of microbial communities between HSP and healthy children, with significant compositional differences. 16S rRNA gene sequencing showed that the relative abundance of key genera, such as Veillonella and Prevotella, differed between the two groups. A random forest algorithm identified five genera as potential diagnostic biomarkers for HSP. Co-occurrence analysis revealed different hub microbes in HSP and healthy children. BugBase predicted an increased proportion of stress-tolerant bacteria in the HSP group compared to the healthy controls group. PICRUSt analysis indicated alterations in metabolic functions of tongue coating microbiota between HSP and healthy children, with 25 KEGG pathways exhibiting significant differences. Children with HSP exhibit marked differences in their tongue coating microbiota when contrasted with their healthy counterparts.