A method of manufacturing a mobile terminal case comprising a three-dimensional curved body having an outer surface with curved circumferential edges, the method comprising: forming the body from a fiber reinforced composite material, the body including the outer surface with a hairline pattern; wherein forming the body comprises: loading the fiber reinforced composite material on an injection mold having the hairline pattern on an internal wall; forming the hairline pattern on an outer surface of the fiber reinforced composite material by compressing the fiber reinforced composite material against the injection mold; and unmolding the fiber reinforced composite material in which the hairline pattern is formed; forming a plastic injection structure at an inside circumferential edge of the body and exposed to the outside, the plastic injection structure being used for fastening the mobile terminal case to a mobile terminal; and forming a gradation paint layer (2, 3) on both the outer surface of the fiber reinforced composite material with the hairline pattern and the plastic injection structure, wherein forming the hairline pattern on the outer surface of the fiber reinforced composite material by compressing the fiber reinforced composite material loaded on the injection mold comprises compressing an outer surface of the fiber reinforced composite material to the inner wall of the injection mold by vacuum compressing a sealed space in which the fiber reinforced composite material is loaded on the injection mold in a chamber having an environment of a predetermined high temperature and high pressure, wherein, advancing from an outer edge to the inside of the mobile terminal case, a transparency of the gradation paint layer increases to reveal the hairline pattern, wherein, advancing from the inside to the outer edge of the mobile terminal case, the transparency of the gradation paint layer decreases to hide the plastic injection structure, and wherein the gradation paint layer is formed by sequentially loading a primer application layer, a translucent coating layer, a gradation coating layer, and a clear coating layer. forming the body from a fiber reinforced composite material, the body including the outer surface with a hairline pattern; wherein forming the body comprises: loading the fiber reinforced composite material on an injection mold having the hairline pattern on an internal wall; forming the hairline pattern on an outer surface of the fiber reinforced composite material by compressing the fiber reinforced composite material against the injection mold; and unmolding the fiber reinforced composite material in which the hairline pattern is formed; loading the fiber reinforced composite material on an injection mold having the hairline pattern on an internal wall; forming the hairline pattern on an outer surface of the fiber reinforced composite material by compressing the fiber reinforced composite material against the injection mold; and unmolding the fiber reinforced composite material in which the hairline pattern is formed; forming a plastic injection structure at an inside circumferential edge of the body and exposed to the outside, the plastic injection structure being used for fastening the mobile terminal case to a mobile terminal; and forming a gradation paint layer (2, 3) on both the outer surface of the fiber reinforced composite material with the hairline pattern and the plastic injection structure, wherein forming the hairline pattern on the outer surface of the fiber reinforced composite material by compressing the fiber reinforced composite material loaded on the injection mold comprises compressing an outer surface of the fiber reinforced composite material to the inner wall of the injection mold by vacuum compressing a sealed space in which the fiber reinforced composite material is loaded on the injection mold in a chamber having an environment of a predetermined high temperature and high pressure, wherein, advancing from an outer edge to the inside of the mobile terminal case, a transparency of the gradation paint layer increases to reveal the hairline pattern, wherein, advancing from the inside to the outer edge of the mobile terminal case, the transparency of the gradation paint layer decreases to hide the plastic injection structure, and wherein the gradation paint layer is formed by sequentially loading a primer application layer, a translucent coating layer, a gradation coating layer, and a clear coating layer.