A USB cable structure includes a cable body and a plurality of wires. The cable body extends a length along an axial direction and forms an inner space, and the inner space forms an elliptical cross-section in the radial section of the cable body perpendicular to the axial direction. The plurality of wires are arranged in the elliptical inner space of the cable body, and the diameter of the wire can be increased by the enlarged elliptical inner space to reduce the attenuation of the transmission signal, thereby extending the length of the transmission cable to transmit the signal to a longer distance without the assistance of the attenuation compensation chip.