A dispersant for nanomaterials is an indispensable additive in nanotechnology, specifically designed to address the severe agglomeration of nanoparticles caused by their enormous specific surface area and high surface energy. Featuring precisely engineered molecular structures, these dispersants utilize anchoring groups to firmly bind to nanoparticle surfaces while extending solvated chains into the surrounding medium, creating powerful steric hindrance and/or introducing electrostatic repulsion. This effectively counteracts the van der Waals forces between nanoparticles, enabling the separation of agglomerated particles into primary individual units and maintaining their stable mono-dispersion during storage and application. Consequently, the unique quantum effects and surface characteristics of nanomaterials in optical, electrical, and mechanical properties can be fully utilized, providing crucial technical support for developing high-performance nanocomposites, conductive inks, catalytic preparations, and biomedical reagents.