Abstract: Diarrhea is a common clinical symptom in children. The main factor responsible for diarrhea is intestinal microecological imbalance. The effect of Qiwei Baizhu powder on infantile diarrhea is remarkable. Intestinal microecology is the hot topic in current research. It is of great significance to elucidate the curative effect of Chinese medicine and the pathogenesis of diarrhea. According to the connotation of microecology and by searching the literature, this article reviews the progress in research of intestinal microbial community structure, intestinal enzyme activity, and intestinal microbial metabolism. It is shown that Qiwei Baizhu powder can repair the intestinal mucosal barrier, inhibit the propagation of harmful bacteria in the intestine, adjust intestinal flora, and improve intestinal enzyme activity by promoting the growth of beneficial bacteria in the gut, especially the activity of intestinal lactase. Qiwei Baizhu powder can regulate the levels of enzyme activity and production. These results can be used to reveal the mechanism of diarrhea to promote the clinical application of Qiwei Baizhu powder.