The utility model relates to an optical-cable welding fixing device. The optical-cable welding fixing device comprises a fixing platform, a base unit, a height adjusting screw, an upper clamping arm, a lower clamping arm and lock nuts. The optical-cable welding fixing device is characterized in that: two ends of the bottom of the base unit are provided with fixing holes, the fixing holes are fixed on the fixing platform through bolts, the lower clamping arm and the upper clamping arm are fixedly connected with the height adjusting screw through the lock nuts, the left and right ends of the upper clamping arm are provided with lower jaws, and the left and right ends of the lower clamping arm are provided with upper jaws corresponding to the lower jaws. The optical-cable welding fixing device is simple to manufacture, low in cost and strong in practicality; and swings, caused by twisting forces, of an optical cable are firmly controlled relying on mechanical strengths, so the optical-cable welding quality is guaranteed, and the welding speed is also improved.