Fiber optic cable is the main information network of all kinds of information network today. If the "Internet" is called "information highway", then, the cable network is the cornerstone of the information highway - fiber optic cable network is the physical routing of the Internet. Once a cable damaged and blocked, the direction of the "information highway" that is destroyed. Through the transmission of information through the cable, in addition to the usual telephone, telegraph, fax, a large number of transmission of television signals, bank transfer, stock market and other moments can not interrupt the information. Long-distance communication cable transmission mode has been developed by the PDH to SDH, the transmission rate has been from the original 140MB / S development to 2.5GB / S, 4 × 2.5GB / S, 16 × 2.5GB / S or even higher, that is, A pair of cores can be opened 30,000, 120,000, 48 million or even more to the development of more ways. Such a large transmission capacity, cable once blocked not only to the telecommunications sector caused huge losses, and because of poor communication, will cause a lot of inconvenience to the masses, such as computer users can not access the Internet, the stock market can not know, bank exchange can not be carried out, Take a bubble, a variety of information can not be transmitted. In the remote mountainous areas, once the cable is interrupted, it will make the county and even along the cable several counties in the communications on the isolation, as an island. The loss caused by the party and government organs and the people is incalculable.