The invention relates to a submarine cable with an increased current-carrying capacity. Conductor layers comprising a plurality of annealed copper wires with high conductivity are tightly distributed at the periphery of a tin-plated copper spiral pipe; a carbon black paper conductor shielding layer, an oil-filled high-voltage cable paper insulating layer, a carbon black paper insulation shielding layer, a copper strip insulation shielding layer and a seamless lead-alloy sheath are wrapped at the periphery of the conductor layers sequentially; asphalt is evenly coated at the periphery of the seamless lead-alloy sheath; and a self-adhesive polyethylene strip inner cushion layer, double stainless steel strip strengthening layers, a self-adhesive polyethylene strip outer cushion layer, a non-woven fabric liner layer, a high-density polyethylene corrosion resisting layer, an armoured inner cushion layer formed by evenly soaking hemp ropes at intervals through polypropylene ropes in a concentric stranding manner, an armoured layer formed by uniform spacing of aluminum-magnesium-plated alloy steel wires and a copper wire in the concentric stranding manner and an outer protecting layer are wrapped at the periphery of the seamless lead-alloy sheath sequentially. The submarine cable has a larger current-carrying capacity and is excellent in water seepage resistance, seawater corrosion resistance, external water pressure resistance, voltage thermal shock resistance and tension bending resistance. In addition, the submarine cable also has the advantages of long service life and high reliability.