A continuous fiber reinforced thermoplastics pre-forming insert injection molded seat back frame, comprising: a pair of frame parts which are coupled to face each other and have fiber reinforced plastic formed therein; and reinforcement parts which are formed on regions that the pair of frames respectively face, and are coupled to each other in multiple locations, and wherein the pair of frame parts comprises: a front frame on which a first coupling region is formed on one surface, and a back frame on which a second coupling region facing with the first coupling region is formed, wherein a facing region comprises the first coupling region and the second coupling region, and wherein the reinforcement parts comprise a plurality of first reinforcement parts which are protrusions formed on the first coupling region and a plurality of second reinforcement parts which are protrusions formed on the second coupling region and coupled with a plurality of first reinforcement ribs, and wherein the plurality of first reinforcement ribs and a plurality of second reinforcement ribs are coupled by being fitted to each other, and wherein the plurality of first reinforcement ribs and the plurality of second reinforcement ribs are coupled to each other by mechanical fastening using a fusion or fastening bolt, and wherein a pointed protrusion is formed downward at the end of the first reinforcement ribs and grooves, to which the pointed protrusion is fitted, are formed at the end of the second reinforcement ribs. a pair of frame parts which are coupled to face each other and have fiber reinforced plastic formed therein; and reinforcement parts which are formed on regions that the pair of frames respectively face, and are coupled to each other in multiple locations, and wherein the pair of frame parts comprises: a front frame on which a first coupling region is formed on one surface, and a back frame on which a second coupling region facing with the first coupling region is formed, wherein a facing region comprises the first coupling region and the second coupling region, and wherein the reinforcement parts comprise a plurality of first reinforcement parts which are protrusions formed on the first coupling region and a plurality of second reinforcement parts which are protrusions formed on the second coupling region and coupled with a plurality of first reinforcement ribs, and wherein the plurality of first reinforcement ribs and a plurality of second reinforcement ribs are coupled by being fitted to each other, and wherein the plurality of first reinforcement ribs and the plurality of second reinforcement ribs are coupled to each other by mechanical fastening using a fusion or fastening bolt, and wherein a pointed protrusion is formed downward at the end of the first reinforcement ribs and grooves, to which the pointed protrusion is fitted, are formed at the end of the second reinforcement ribs. a front frame on which a first coupling region is formed on one surface, and a back frame on which a second coupling region facing with the first coupling region is formed, wherein a facing region comprises the first coupling region and the second coupling region, and wherein the reinforcement parts comprise a plurality of first reinforcement parts which are protrusions formed on the first coupling region and a plurality of second reinforcement parts which are protrusions formed on the second coupling region and coupled with a plurality of first reinforcement ribs, and wherein the plurality of first reinforcement ribs and a plurality of second reinforcement ribs are coupled by being fitted to each other, and wherein the plurality of first reinforcement ribs and the plurality of second reinforcement ribs are coupled to each other by mechanical fastening using a fusion or fastening bolt, and wherein a pointed protrusion is formed downward at the end of the first reinforcement ribs and grooves, to which the pointed protrusion is fitted, are formed at the end of the second reinforcement ribs.