<p>Soil contamination by heavy metals, primarily due to human activities, poses significant ecological and human and ecological health risks. Biochar, a porous carbonaceous material characterized mainly by microporous structures (&lt; 2&#xa0;nm), with mesopores (2–50&#xa0;nm) and macropores (&gt; 50&#xa0;nm) present in smaller proportions, produced by pyrolyzing carbon-rich biomass under oxygen-limited conditions, has been widely studied as a soil amendment and microbial habitat. Although biochar’s potential for soil remediation has been explored, the mechanisms by which it synergistically interacts with microorganisms to enhance soil health remain poorly understood. This paper reviews the combined effects of biochar and microorganisms on soil improvement, focusing on biochar’s impact on soil physical, chemical, and biological properties. It examines how biochar enhances soil water retention, fertility, and supports microbial communities, contributing to soil ecosystem restoration and promoting plant growth. The review also addresses current challenges and identifies future research directions for integrating biochar and microorganisms in contaminated soil remediation. The goal is to support the development of sustainable agricultural practices and environmental protection, offering insights into the broader application of biochar.</p> Graphical Abstract <p></p>