A high-strength PC steel wire, having a chemical composition containing, in mass%, C: 0.90 to 1.10%, Si: 0.80 to 1.50%, Mn: 0.30 to 0.70%, P: 0.030% or less, S: 0.030% or less, Al: 0.010 to 0.070%, N: 0.0010 to 0.010%, Cr: 0 to 0.50%, V: 0 to 0.10%, B: 0 to 0.005%, Ni: 0 to 1.0%, Cu: 0 to 0.50%, and the balance: Fe and impurities; wherein: when a diameter of the steel wire is represented by D, a ratio between a Vickers hardness at a location 0.1D from a surface of the steel wire and a Vickers hardness of a region on an inner side relative to the location 0.1D from the surface of the steel wire satisfies formula (i) below, a steel micro-structure in a region from the surface to a depth of 0.01D of the steel wire comprises, in area%: pearlite structure: less than 80%, and the balance: a ferrite structure, a bainitic structure, or a ferrite structure and a bainitic structure; a steel micro-structure in a region on an inner side relative to the region from the surface to a depth of 0.01D of the steel wire comprises, in area%: pearlite structure: 95% or more; and a tensile strength is 2000 to 2400 MPa; 1.10 < Hv S / Hv I ≤ 1.15 where, the meaning of each symbol in the formula (i) is as follows: Hvs: Vickers hardness of the location 0.1D from the surface of the steel wire; Hvi: an average value of the Vickers hardness at a location at a depth of 0.25D and a location at a depth of 0.5D from the surface. when a diameter of the steel wire is represented by D, a ratio between a Vickers hardness at a location 0.1D from a surface of the steel wire and a Vickers hardness of a region on an inner side relative to the location 0.1D from the surface of the steel wire satisfies formula (i) below, a steel micro-structure in a region from the surface to a depth of 0.01D of the steel wire comprises, in area%: pearlite structure: less than 80%, and the balance: a ferrite structure, a bainitic structure, or a ferrite structure and a bainitic structure; a steel micro-structure in a region on an inner side relative to the region from the surface to a depth of 0.01D of the steel wire comprises, in area%: pearlite structure: 95% or more; and a tensile strength is 2000 to 2400 MPa; 1.10 < Hv S / Hv I ≤ 1.15 where, the meaning of each symbol in the formula (i) is as follows: Hvs: Vickers hardness of the location 0.1D from the surface of the steel wire; Hvi: an average value of the Vickers hardness at a location at a depth of 0.25D and a location at a depth of 0.5D from the surface. pearlite structure: less than 80%, and the balance: a ferrite structure, a bainitic structure, or a ferrite structure and a bainitic structure; a steel micro-structure in a region on an inner side relative to the region from the surface to a depth of 0.01D of the steel wire comprises, in area%: pearlite structure: 95% or more; and a tensile strength is 2000 to 2400 MPa; 1.10 < Hv S / Hv I ≤ 1.15 where, the meaning of each symbol in the formula (i) is as follows: Hvs: Vickers hardness of the location 0.1D from the surface of the steel wire; Hvi: an average value of the Vickers hardness at a location at a depth of 0.25D and a location at a depth of 0.5D from the surface. pearlite structure: 95% or more; and a tensile strength is 2000 to 2400 MPa; 1.10 < Hv S / Hv I ≤ 1.15 where, the meaning of each symbol in the formula (i) is as follows: Hvs: Vickers hardness of the location 0.1D from the surface of the steel wire; Hvi: an average value of the Vickers hardness at a location at a depth of 0.25D and a location at a depth of 0.5D from the surface. Hvs: Vickers hardness of the location 0.1D from the surface of the steel wire; Hvi: an average value of the Vickers hardness at a location at a depth of 0.25D and a location at a depth of 0.5D from the surface.