The invention discloses a downhole optical cable connecting and protecting device which comprises a sleeve (10), two sealing plugs (20), two sealing rings (11), two end covers (30) and two tensile cones (40), wherein the sleeve (10) is a hollow cylinder in which a connecting part of an optical cable is contained; the two sealing plugs (20) are respectively installed at two ends of the sleeve (10) for sealing the sleeve (10); the two sealing rings (11) are respectively installed between the sleeve (10) and the sealing plugs (20); the two end covers (30) are respectively installed at one end of each sealing plug (20) far from the sleeve (10); and the two tensile cones (40) are installed between the end covers (30) and the sealing plugs (20) and matched with the end covers (30) for tensioning the optical cable. The downhole optical cable connecting and protecting device provided by the invention realizes connection with the optical cable and ensures the strength of connection through the tensile cones, adopts the sealing plugs and the sealing rings for sealing, and has convenient operation and good sealing effect.