A flat data transmission cable includes a plurality of juxtaposed wires, a plastic layer enclosing on the wires integrally and a metallic layer formed by a metal material belt arranged on an outer side of the plastic layer in a spiral winding way, each wire has a conductor. The metallic layer has at least an aluminum foil layer and a bonding layer arranged on the side of the aluminum foil layer facing to the plastic layer, the metallic layer is bonded to the outer side of the plastic layer by the bonding layer.