The invention discloses an optical network distribution unit applied to a communication network device. The device comprises a second optical network distribution unit, as well as a first main optical fiber link and a second main optical fiber link which are respectively provided with at least one real-time switch, wherein each real-time switch is equipment based on a packet transport network PTN and an Ethernet passive optical network (EPON); a first PON port of the optical network distribution unit is used for being connected with a first PON port of the second optical network distribution unit by virtue of the first main optical fiber link; a second PON port of the optical network distribution unit is used for being connected with a second PON port of the second optical network distribution unit by virtue of the second main optical fiber link; the optical network distribution unit respectively simultaneously transmits the same service data to the second optical network distribution unit by utilizing the first PON port through the first main optical fiber link and by utilizing the second PON port through the second main optical fiber link, so that when one main optical fiber link fails, the service data also can be transmitted to the second optical network distribution unit by virtue of the other main optical fiber link. Therefore, normal service operation is guaranteed.