A method of manufacturing a high-density fiber reinforced ceramic composite material, comprising the steps of: 1) impregnating a fiber preform material multi-coated with pyrolytic carbon and silicon carbide with a slurry in which a phenol resin is mixed with a filler including carbon powder and metal silicon powder, to form a impregnated fiber reinforced plastic composite material; 2) carbonizing the impregnated fiber reinforced plastic composite material to form a carbonized fiber composite material; 3) heat-treating the carbonized fiber composite material in a vacuum atmosphere to melt the filler and then diffusing the molten filler into the carbonized fiber composite material to obtain a primarily reaction-sintered fiber composite material, as a primary reaction-sintering of the fiber composite material; 4) cooling the primarily reaction-sintered fiber composite material down to room temperature and then impregnating the primarily reaction-sintered fiber composite material with a solution in which a polymer precursor for producing silicon carbide (SiC) is dissolved in a hexane (n-hexane) solvent; and 5) applying metal silicon powder onto the surface of the primarily reaction-sintered fiber composite material impregnated with the polymer precursor to bring the metal silicon powder into contact with the primarily reaction-sintered fiber composite material, melting the metal silicon powder in a vacuum atmosphere and then diffusing the molten metal silicon powder into the primarily reaction-sintered fiber composite material to obtain a secondarily reaction-sintered fiber composite material, as a secondary reaction-sintering of the fiber composite material. 1) impregnating a fiber preform material multi-coated with pyrolytic carbon and silicon carbide with a slurry in which a phenol resin is mixed with a filler including carbon powder and metal silicon powder, to form a impregnated fiber reinforced plastic composite material; 2) carbonizing the impregnated fiber reinforced plastic composite material to form a carbonized fiber composite material; 3) heat-treating the carbonized fiber composite material in a vacuum atmosphere to melt the filler and then diffusing the molten filler into the carbonized fiber composite material to obtain a primarily reaction-sintered fiber composite material, as a primary reaction-sintering of the fiber composite material; 4) cooling the primarily reaction-sintered fiber composite material down to room temperature and then impregnating the primarily reaction-sintered fiber composite material with a solution in which a polymer precursor for producing silicon carbide (SiC) is dissolved in a hexane (n-hexane) solvent; and 5) applying metal silicon powder onto the surface of the primarily reaction-sintered fiber composite material impregnated with the polymer precursor to bring the metal silicon powder into contact with the primarily reaction-sintered fiber composite material, melting the metal silicon powder in a vacuum atmosphere and then diffusing the molten metal silicon powder into the primarily reaction-sintered fiber composite material to obtain a secondarily reaction-sintered fiber composite material, as a secondary reaction-sintering of the fiber composite material.