Objective: To explore the dynamic correlation and clinical prognostic value between the diversity of gut microbiota alpha and trace elements in children with infectious diarrhea. Methods: A prospective study was conducted on 100 children with infectious diarrhea admitted from January 2022 to January 2025. Fecal samples were collected from all children, and gene DNA was extracted using the cetyltrimethylammonium bromide (CTAB) method. 16Sr DNA sequencing was performed to analyze Chao1 index, Simpson index, Shannon index, and bacterial count, reflecting the alpha diversity of the gut microbiota. According to quartiles, the alpha diversity of the gut microbiota was divided into high and low groups. Compare the levels of trace elements in the blood between the high and low groups. Analyze the correlation between gut microbiota alpha diversity and trace elements before and after treatment. Subsequently, 100 pediatric patients were divided into two subgroups based on clinical prognosis, namely the good prognosis group (n=80) and the poor prognosis group (n=20). The Chao1 index, Simpson index, Shannon index, and bacterial species were compared between the two groups, and logistic regression was used to analyze the prognostic value of gut microbiota alpha diversity for infectious diarrhea. Results: The expression levels of calcium, iron, zinc, and copper in the high Chao1 group were higher than those in the low Chao1 group (P<0.05). There was no significant difference in the expression levels of calcium, iron, zinc, and copper between the high Simpson group and the low Simpson group (P>0.05). The expression levels of calcium, iron, zinc, and copper in the high Shannon group were higher than those in the low Shannon group (P<0.05). The expression levels of calcium, iron, zinc, and copper in the high strain group were higher than those in the low strain group (P<0.05); Correlation analysis showed that Chao1 index, Shannon index, and bacterial species number were significantly positively correlated with the four trace elements (r=0.389~0.689, all P<0.05), while the Simpson index did not reach statistical significance with each trace element (P>0.05); The Chao1 index, Shannon index, and bacterial count in the good prognosis group were higher than those in the poor prognosis group (P<0.05), while there was no significant difference in Simpson index between the good prognosis group and the poor prognosis group (P>0.05); Multivariate logistic regression analysis showed that Chao1 index, Shannon index, and bacterial count have independent predictive value for the prognosis of infectious diarrhea (P<0.05). Conclusion: The alpha diversity of intestinal microbiota in children with infectious diarrhea is closely related to the levels of trace elements such as calcium, iron, zinc, and copper in the blood. At the same time, the Chao1 index, Shannon index, and bacterial count in the alpha diversity of intestinal microbiota can serve as independent predictive indicators for clinical prognosis of infectious diarrhea in children.