Indoxyl sulfate (IS), a protein-bound indole toxin, is currently a key research focus regarding uremic toxins and renal injury both in China and internationally. Studies have shown that IS can upregulate the expression of TGF-β1, TIMP-1, and pro-α1 (I), induce the production of free radicals, decrease superoxide scavenging activity, and promote the apoptosis of renal tubular epithelial cells, thereby exacerbating renal damage. As metabolomics research progresses, IS is emerging as a potential new biomarker for kidney injury. This paper reviews the progress of research on the application of IS in kidney injury over the past decade, drawing on resources from databases such as the CNKI and PubMed. The aim is to provide insights that can aid in clinical individualized treatment, enhancing the safety and effectiveness of patient care.