The invention relates to a method for preparing a conductive polymer/silsesquioxane composite electrode material, which comprises two reactions that: silsesquioxane with end benzene ring and sulfonating agent undergo sulfonation reaction to form a phenyl sulfonic acid group, silsesquioxane with end mercapto and oxidant undergo oxidation reaction to form a sulfonic acid group, and the silsesquioxane and an intrinsic conductive polymer monomer undergo in situ polymerization to form the composite electrode material. The method has simple process and low cost; the prepared conductive polymer nano composite material has good electric conductivity (more than 5S/m) and large specific surface area; and a super capacitor prepared from the electrode material has the characteristics of high specific power, high specific energy, good recyclability and the like, and has good application prospect.