Abstract: As an emerging functional composite material, iron-modified biochar combines the structural characteristics of biochar with the high redox activity of iron, exhibiting excellent catalytic performance and environmental stability. This material has attracted extensive attention in the fields of wastewater treatment, soil and water environment remediation in recent years. This study applies CiteSpace software to perform a bibliometric analysis with visualization of iron-modified biochar research dynamics, based on the Web of Science Core Collection dataset, aiming to comprehensively understand the research hotspots and development trends of iron-modified biochar. The results reveal a consistent increase in publications on iron-modified biochar since 2011, with particularly rapid growth observed over the past five years. China dominates this field, producing the highest number of publications. Zero-valent iron modification is the most extensively studied approach, while magnetic properties represent the most investigated characteristics of iron-modified biochar. Its functionality primarily relies on three mechanisms: adsorption, catalytic activity, and serving as a reaction carrier. Research hotspots have shifted from the initial focus on phosphate removal in sewage to various fields such as wastewater treatment, soil and water environment remediation, and bioenergy production. Concurrently, research attention has transitioned from simple effects to intrinsic mechanisms, special function enhancement, and low-cost preparation methods. Future research should continue to deepen the understanding of the functional mechanisms and key characteristics strengthening pathways of iron-modified biochar, expand its application areas, explore sustainable preparation strategies from a functional materials development perspective, and advance the large-scale, green, and low-cost application of this material.