Optical line protection (OLP) system is a new optical line protection subsystem developed with advanced technology of dynamic and synchronous optical switches. When communication quality is lower or equipment breaks down due to accidental fracture or bigger loss of optical fiber in the optical transmission line, the OLP system can switch the primary line to the secondary line within a short time, to ensure normal operation communication of line, which effectively prevent fiber or equipment fault and shorten the recovery time from hours to milliseconds.