One silsesquioxane-polythiophene hybrid copolymer, with combined star-like structure and intramolecular heterogeneity, was synthesized and sufficiently characterized via various methods, including FTIR, NMR, and SEC measurements. According to the exploration and characterization results, it was much more efficient at modifying SWNTs than its linear analogs in aqueous solution. The hydrophobic silsesquioxane core and PEDOT chains could locally anchor to the surface of the nanotubes, while the soluble flexible copolymer chains extended into the solution and rigid conjugated chains provided some π - π stacking effect to enhance adhesive force with the conjugated structure of the carbon nanotube, imparting steric stabilization to nanotube dispersion. The noncovalent interaction with SWNTs and solubility in aqueous solution improved the electrochemical characteristics of the modified-SWNT composite and availed for the preparation of a flexible and transparent electroactive film. Accordingly, this kind of silsesquioxane-polythiophene hybrid copolymer will be forwarded to apply to the assembling of flexible optoelectronic devices.