Cyclic bottlebrush polymers were synthesized and used as single molecular templates to prepare donut-shaped hybrid nanoparticles with organo-silica cross-linked and gold nanocluster coordinated internal structures. "Grafting-onto" strategy was adopted to prepare cyclic bottlebrush polymers by combining ring-expansion metathesis polymerization (REMP), reversible addition fragmentation chain transfer (RAFT) polymerization, and triazolinedione (TAD)-diene click reaction. In this approach, cyclic poly(norbornene imide) backbones with diene side groups (C-PNB-diene) were synthesized based on REMP technique. TAD-terminated diblock copolymer side chains were produced from RAFT polymerization including TAD-terminated poly(3-(triethoxysilyl)propyl methacrylate)-block-poly(oligo(ethylene glycol) methacrylate) (TAD-PTEPM-b-POEGMA) and TAD-terminated poly(glycidyl methacrylate)-block-poly(oligo(ethylene glycol) methacrylate) (TAD-PGMA-b-POEGMA). The cyclic bottlebrush polymers 1 and 2 were then prepared by virtue of TAD-diene click reaction to graft TAD-PTEPM-b-POEGMA and TAD-PGMA-b-POEGMA side chains onto C-PNB-diene backbones, respectively. Furthermore, the donut-shaped hybrid nanoparticles with organo-silica cross-linked internal structures were obtained by in situ cross-linking PTEPM domains of the cyclic bottlebrush polymer 1 templates. For the formation of donut-shaped hybrid nanoparticles coordinating gold nanoclusters inside, the cyclic bottlebrush polymer 2 templates were first postmodified to introduce the functional pyridine groups inside the PGMA domains, which were then used as location to coordinate the gold nanoclusters.