Low-attenuation signal transmission cable

The invention discloses a low-attenuation signal transmission cable. One of seven tin-coated copper wires is arranged at the center position, and other six tin-coated copper wires are stranded and arranged at the outer surface of the central tin-coated copper wire; a steel layer covers the outer surface of a first steel layer, and a second steel layer covers the outer surface of the steel layer; the first steel layer and the inner surface of the steel layer are connected in a sealed manner through a first alloy layer, and the second steel layer and the outer surface of the steel layer are connected in a sealed manner through a second alloy layer; an outer protection layer covers the outer surface of the second steel layer; and the second alloy layer is composed of 25% copper, 69% iron, 3% molybdenum, 2% chromium and 1% carbon. The low-attenuation signal transmission cable is capable of absorbing a magnetic field in an electromagnetic field, and the shielding performance of an electric field is improved after two times of absorption.