Method, system and device for realizing passive optical network optical fiber protection

The invention discloses a method, a system and a device for realizing passive optical network optical fiber protection, wherein the method comprises the steps that two upper connection ports of each optical network unit in a pair of optical network units are respectively connected with the lower connection ports of a first optical circuit terminal and a second optical circuit terminal; each edge router connected with the first optical circuit terminal and the second optical circuit terminal bears one business, and different lower connection ports are respectively connected with the upper connection ports of the first optical circuit terminal and the second optical circuit terminal; and two links of each optical network unit, which reach the same edge router via the first optical circuit terminal and the second optical circuit terminal, are configured into two links protecting each other. The invention focuses on realizing the protection of all optical fiber links of XPON and the protection based on the busine