The invention provides an optical line protection system. The system comprises four stations. A first station communicates with the other three stations through a data communication network. A first automatic optical switch module and a first optical fiber wiring line are arranged at a second station. A second optical fiber wiring line, a general optical amplifier module and a third optical fiber wiring line are arranged at a third station. A fourth optical fiber wiring line and a second automatic optical switch module are arranged at a fourth station. The problem that duration of online detection and automatic switching is too long in an existing optical fiber protection system is solved.