The invention discloses a POTN service forwarding system and a forwarding method and relates to the technical field of POTN transmission. The system comprises an Ethernet branch disk, a switch disk and OTN line disks. POVE is instantiated to multicast in an up direction to realize bridging, packet services take the multicast as an outlet of an up direction service channel, and an OTN service takes the multicast as a source port interacting with an ODUK channel; the POVE is instantiated to VLANDOMAIN in a down direction to realize bridging, the OTN service maps a line side back plate port connected to the ODUK channel to the VLANDOMAIN, and the packet services take the VLANDOMAIN as a common physical port to complete classification processing of the packet services. The invention also discloses a POTN service forwarding method.