An organic-inorganic hybrid polymer composed of a Dawson trivanadium-substituted heteropolytungstate ((Bu4N)5[H4P2W15V3O62]) cluster and PS chain are originally designed and first synthesized via in situ ATRP. Further characterization includes NMR spectroscopy, FT-IR spectroscopy, and GPC which proved the purity of the material. By means of a cation exchange process, a hybrid polymer (Bu4N)(+)-POM-PS was tuned into a novel giant amphiphile H+-POM-PS. Immediately, individual molecules self-assembled into kinetically favored hybrid vesicles in DMF. Our work provides a controllable and rational way to fabricate stable and well-defined POM-polymer hybrid polymers that can be optimized for potential applications.