A forwarding table generation method, comprising: determining (210; 504; 605), by a forwarding device, a first timeslot set, wherein the first timeslot set comprises multiple timeslots used when the forwarding device sends, to a first device by using a first flexible Ethernet group, FlexE group, multiple encoded data blocks generated by a physical coding sublayer, and the multiple timeslots comprised in the first timeslot set are in a one-to-one correspondence with the multiple encoded data blocks; determining (220; 510, 606), by the forwarding device, a second timeslot set, wherein the second timeslot set comprises multiple timeslots used when the forwarding device receives, by using a second FlexE group, the multiple encoded data blocks sent by a second device, and the multiple timeslots comprised in the second timeslot set are in a one-to-one correspondence with the multiple encoded data blocks; and generating (230; 511; 607), by the forwarding device, a forwarding table, wherein the forwarding table comprises a mapping relationship between the multiple timeslots comprised in the second timeslot set of the second FlexE group, and the multiple timeslots comprised in the first timeslot set of the first FlexE group; wherein before the determining (210; 504; 605), by a forwarding device, a first timeslot set, the method further comprises: receiving, by the forwarding device, a path message sent by the second device, wherein the path message comprises traffic parameter attribute information, the traffic parameter attribute information comprises a signal type field and a bit_rate field, the signal type field represents that a type of a transmitted signal is an encoded data block whose rate is 5 gigabit per second, Gbps, and the bit_rate field represents a rate of a flexible Ethernet client corresponding to the multiple encoded data blocks, wherein the flexible Ethernet client is an Ethernet flow; and forwarding, by the forwarding device, the path message to the first device. determining (210; 504; 605), by a forwarding device, a first timeslot set, wherein the first timeslot set comprises multiple timeslots used when the forwarding device sends, to a first device by using a first flexible Ethernet group, FlexE group, multiple encoded data blocks generated by a physical coding sublayer, and the multiple timeslots comprised in the first timeslot set are in a one-to-one correspondence with the multiple encoded data blocks; determining (220; 510, 606), by the forwarding device, a second timeslot set, wherein the second timeslot set comprises multiple timeslots used when the forwarding device receives, by using a second FlexE group, the multiple encoded data blocks sent by a second device, and the multiple timeslots comprised in the second timeslot set are in a one-to-one correspondence with the multiple encoded data blocks; and generating (230; 511; 607), by the forwarding device, a forwarding table, wherein the forwarding table comprises a mapping relationship between the multiple timeslots comprised in the second timeslot set of the second FlexE group, and the multiple timeslots comprised in the first timeslot set of the first FlexE group; wherein before the determining (210; 504; 605), by a forwarding device, a first timeslot set, the method further comprises: receiving, by the forwarding device, a path message sent by the second device, wherein the path message comprises traffic parameter attribute information, the traffic parameter attribute information comprises a signal type field and a bit_rate field, the signal type field represents that a type of a transmitted signal is an encoded data block whose rate is 5 gigabit per second, Gbps, and the bit_rate field represents a rate of a flexible Ethernet client corresponding to the multiple encoded data blocks, wherein the flexible Ethernet client is an Ethernet flow; and forwarding, by the forwarding device, the path message to the first device. receiving, by the forwarding device, a path message sent by the second device, wherein the path message comprises traffic parameter attribute information, the traffic parameter attribute information comprises a signal type field and a bit_rate field, the signal type field represents that a type of a transmitted signal is an encoded data block whose rate is 5 gigabit per second, Gbps, and the bit_rate field represents a rate of a flexible Ethernet client corresponding to the multiple encoded data blocks, wherein the flexible Ethernet client is an Ethernet flow; and forwarding, by the forwarding device, the path message to the first device.