Lightning is an electrical discharge within clouds either from cloud to cloud or from cloud to the earth. It has great impacts on communication stations and other signal circuits. For example, it will not only affect all DWDM fiber channels in short bursts, but also affect transmission directions simultaneously according to numerous researches. It will even cause a fire when there are high current lightning discharges. Although the signals in fiber cables are optical signals, most of the outdoor optical cables using reinforced cores or armored optical cables are easy to get damaged under lightning because of the metal protective layer inside the cable. Therefore, it is important to build a lightning protection system for fiber optic cables.