DSS cable adopts the twisted structure of loose sleeve layer, 250 μm optical fiber is inserted into the loose tube made of high modulus materials, and the loose tube is filled with waterproof compounds. The loose tube ( and filling rope ) is twisted around the non-metallic center reinforcing core ( FRP ) to synthesize a compact cable core. The gap of the cable core is filled with a water-blocking yarn and a water-blocking belt longitudinally wrapped by the cable core, and then the aramid fiber that plays a reinforcing role is twisted. Finally, the polyethylene ( PE ) outer sheath or the electric mark ( AT ) outer sheath is extruded.