The invention discloses a direct-current cable for rail transit, which comprises a sheath layer, a flame retardant layer, a water blocking layer, an insulator and a conductor, the insulator wraps theouter surface of the conductor, the water blocking layer is arranged on the outer surface of the side edge of the insulator, the flame retardant layer is wound on the outer surface of the water blocking layer, and the sheath layer is extruded on the outer surface of the side edge of the water blocking layer. The insulator is arranged between the conductor and the water-blocking layer, and the flame-retardant layer is arranged between the water-blocking layer and the sheath layer. According to the direct-current cable for rail transit, the direct-current cable for rail transit has a multi-protection structure, the bending effect of the direct-current cable for rail transit is improved, the cracking phenomenon of the direct-current cable for rail transit during bending laying is avoided, andmeanwhile, the waterproof effect of the direct-current cable for rail transit is improved; and therefore, the direct-current cable can be used underwater for a long time, and the safety of the direct-current cable in use is improved.