The present invention relates to a method for preparing a high molecular weight latex resin powder, and more precisely, a method for preparing a high molecular weight latex resin powder which comprises the steps of preparing a slurry by coagulating a high molecular weight latex; stabilizing the slurry; and aging the stabilized slurry, and is characterized by the direct addition of a colloidal modifier to the high molecular weight latex reactant during the preparation of the slurry. According to the present invention, the high molecular weight latex resin powder prepared by the method of the present invention has excellent particle size distribution, apparent specific gravity, caking property and thermo-stability, even with high solid content, compared with the conventional slow coagulation, and at the same time the method has an advantage of reducing energy costs and waste water generation.