The invention discloses a flexible optical fiber ribbon optical cable with a large number of cores, which comprises a water blocking tape, a loose tube, an inner sheath, a middle sheath, and an outer sheath arranged from the inside to the outside, and the optical fiber ribbon matrix is arranged on the loose tube Inside, multiple Kevlar fiber bundles are evenly arranged between the inner and outer walls of the loose tube. The invention can solve the technical problem that the existing large-core optical fiber ribbon cable cannot achieve extreme bending radius, and the tensile performance is poor at the same time, and because the strengthening core has a large bending internal stress in an extremely bending application environment, it will affect the optical cable. Structural integrity, and technical issues that may damage the optical fiber. The invention also discloses a middle sheath processing device for large-core flexible optical fiber ribbon cable, which includes an inner sheath, a driving screw, an auxiliary screw, galvanized straight steel wires, and a pair of pressing driving wheels engaged with each other.