The structure of the standard figure-eight self-supporting stranded optical cable is that single-mode or multi-mode optical fiber is sheathed in a loose tube made of high modulus plastic, and the tube is filled with water blocking compound. The center of the cable core is a metal reinforced core. For certain fiber optic cables, a layer of polyethylene needs to be squeezed outside the metal reinforced core. The loose tube (and filler rope) is twisted around the central reinforced core to form a compact and round cable core, the gap in the cable core is filled with water blocking filler. The cable core is longitudinally wrapped with steel-plastic composite tape, and placed in parallel with the steel strands while extruding a figure-eight sheath into a cable.