The present invention relates to a process for preparing a highly active metallocene catalyst supported on polymer bead for olefin polymerization, a metallocene catalyst prepared by the said process and a method for alkylene polymerization by employing the said catalyst. The process for preparing a highly active metallocene catalyst supported on polymer bead for olefin polymerization which comprises the steps of: dissolving divinylbenzene, vinylbenzylchloride, and an initiator in an organic solvent, mixing it with a suspension stabilizer of aqueous phase, and carrying out suspension-polymerization at the temperature of 40 to 80° C. to obtain polystyrene; swelling the polystyrene in dialcoholamine dissolved in an organic solvent at ambient temperature for 1 to 3 days, to give a polymer having a functional group of dialcoholamine; and, reacting the polymer with a metallocene compound (CpM*Cl3) dissolved in an organic solvent. The metallocene catalyst of the present invention can be used widely for ethylene polymerization, styrene polymerization and copolymerization, while replacing the conventional homogeneous catalysts.