Supramolecular chemistry has been widely applied in biomedical fields. It was reported that the topological structure has effects on the performance of gene delivery systems. Supramolecular polymer-like gene carriers with hyperbranched topological structures have still not been reported. In this work, a series of ethanolamine-functionalized polyglycidyl methacrylate (PGMA)-armed AB2 type macromonomers were synthesized based on atom transfer radical polymerization. The AB2 type macromonomers can self-assemble into supramolecular hyperbranched polymers by the host–guest interaction between adamantane and β-cyclodextrin. The biophysical properties of self-assembled and dissembled supramolecular hyperbranched polycations were evaluated in detail. The self-assembled supramolecular polycations with hyperbranched structures possessed higher pDNA condensation ability and much better gene transfection performances than the dissembled AB2 type counterparts. The present work would provide a new venue for designing advanced high-performance supramolecular hyperbranched nucleic acid-delivery systems.