Abstract: The practical application of magnetic nanomaterials (MNMs) in the analytical field is constrained by the agglomeration problem resulting from their high surface energy. Surface modification is a crucial approach to enhance their stability and functionality. By leveraging their bifunctional characteristics, silane coupling agents (SCA) can effectively construct functionalized interfaces on the surface of MNMs, providing a novel strategy to improve adsorption performance. This article systematically reviews the physical and chemical modification methods of MNMs, focusing on the modification mechanisms of SCA, including the silanization reaction driven by hydrolysis and condensation, as well as the regulation of this process by factors such as catalysts, solvent effects, and molecular structure. Furthermore, this study summarizes the enhancing effects of SCA modification on the dispersibility, surface activity, and adsorption performance of MNMs, and reviews its progress in the trace analysis of heavy metals, organic pollutants, and complex matrices. Finally, this paper addresses the current issues of insufficient stability and environmental risks associated with SCA modification. It also looks forward to the prospects of SCA modification processes and the construction of novel MNMs, aiming to expand the application potential of SCA-modified MNMs in the analytical field.