The diameter of the high-voltage conductor is often several times that of the low-voltage conductor. In order to increase the flexibility and bendability of the high-voltage conductor, the conductor core with a larger interface is formed by twisting multiple single wires with smaller diameters. The wire core stranded by multiple single wires has good flexibility and large curvature. When the wire core is bent, the inner and outer parts of the center line of the wire core can move to compensate each other, and the plastic deformation of the conductor will not be caused during bending, so the softness of the wire core. The performance and stability are greatly improved. Therefore, vehicle wiring harnesses, especially high-voltage wires, are generally produced using stranded conductors.