Plus/minus 500kV trapezoidal line conductor copper wire shielding optical fiber composite direct current cable

The invention discloses a plus/minus 500kV trapezoidal line conductor copper wire shielding optical fiber composite direct current cable. The cable comprises a large-section trapezoidal line conductor, a conductor shielding layer, an insulating layer, an insulating and shielding layer, a first semi-conductive water-blocking buffer layer, optical fiber units, a copper wire composite copper strip shielding layer, a second semi-conductive water-blocking buffer layer, an aluminium plastic composite band, an insulating outer sheath and a semi-conductive layer, wherein the large-section trapezoidal line conductor is formed by a central cable core and trapezoidal copper single wires on the outer layer in a stranding manner in different layers; and according to different conductor section requirements, the trapezoidal copper single wires on the outer layer are formed by the following way, the central cable core is formed by one circular copper single line or multiple circular single lines in a tightly-pressing and stranding manner, and 1-6 layers of unequal SZ-shaped copper single wires are arranged on the exterior of the central cable core in a stranding manner. The cable adopts the large-section trapezoidal line conductor; the conductor is stable and tight in structure, and the filling coefficient is not less than 93%; and under the same current-carrying capability, the conductor provided by the invention has a smaller conductor diameter compared with a tightly-pressed circular conductor or a cut conductor, so that the cost input of the overall cable is greatly reduced.