The invention provides an external casing packer armored optical cable penetration tool. A penetration channel is pre-formed in the axial direction of the pipe wall of a filling valve system, a conical seal joint is arranged at an upper port of the penetration channel, the conical seal joint is matched with a armored optical cable and then is sealed in the upper port of the penetration channel, the lower portion s connected with an inner-layer base pipe and an outer-layer base pipe along the wall of the penetration channel, the lower ends of the inner-layer base pipe and the outer-layer base pipe are fixedly connected with lower retainer rings, a penetration channel identical to the filling valve system and a conical seal joint are arranged in the axial direction of the tubular walls of the lower retainer rings, a armored optical cable penetration guide groove is formed outside the inner base pipe, a packing rubber cylinder is arranged outside the outer-layer pipe, the upper end of the packing rubber cylinder is fixedly connected with the outer wall of the filling valve system, the lower end of the packing rubber cylinder is fixedly connected with a floating head, the floating head is in airtight sliding fit with the outer-layer pipe, and an annular gap for communication is reserved between a filling channel of the filling valve system and the outer-layer pipe and the packing rubber cylinder. The external casing packer armored optical cable penetration tool meets the penetration demand of a filling type external casing packer armored optical cable used in a naked eye mode, achieves expansion of a complicated annulus under the large-well-diameter condition, and accordingly construction success rate is ensured.