A synchronization method, comprising: forming N data frames, a frame header of each of the N data frames comprising an identical frame header sequence, N being greater than 1 and less than or equal to the number of lanes M, and M being an integer not less than 2; and sending the N data frames via N lanes, wherein different data frames are sent via different lanes, wherein the forming N data frames comprises inserting the frame header sequence into the frame header of each of the N data frames, the frame header sequence is configured to perform frame synchronization between a receiving end and a sending end or to check frame synchronization; wherein the frame header of each of the N data frames further comprises system synchronization information; system synchronization information of different data frames sent at the same time is different; and the system synchronization information is configured to provide basis for the receiving end to detect system synchronization, wherein the system synchronization information and lane identification information of the lanes have a mapping relationship; sending the N data frames via the N lanes is: determining a lane for sending each of the N data frames according to the system synchronization information; and carrying and sending each of the N data frames in the determined lane; and wherein the synchronization method is characterized in that, the system synchronization is synchronization on the basis of the frame synchronization, and is configured to determine a transmission time delay, the system synchronization information is configured to directly or indirectly indicate predetermined time at which the N data frames reach the receiving end to enable the receiving end to determine, after receiving the N data frames, that the system synchronization is abnormal when two pieces of system synchronization information in any two of the N data frames are identical. forming N data frames, a frame header of each of the N data frames comprising an identical frame header sequence, N being greater than 1 and less than or equal to the number of lanes M, and M being an integer not less than 2; and sending the N data frames via N lanes, wherein different data frames are sent via different lanes, wherein the forming N data frames comprises inserting the frame header sequence into the frame header of each of the N data frames, the frame header sequence is configured to perform frame synchronization between a receiving end and a sending end or to check frame synchronization; wherein the frame header of each of the N data frames further comprises system synchronization information; system synchronization information of different data frames sent at the same time is different; and the system synchronization information is configured to provide basis for the receiving end to detect system synchronization, wherein the system synchronization information and lane identification information of the lanes have a mapping relationship; sending the N data frames via the N lanes is: determining a lane for sending each of the N data frames according to the system synchronization information; and carrying and sending each of the N data frames in the determined lane; and wherein the synchronization method is characterized in that, the system synchronization is synchronization on the basis of the frame synchronization, and is configured to determine a transmission time delay, the system synchronization information is configured to directly or indirectly indicate predetermined time at which the N data frames reach the receiving end to enable the receiving end to determine, after receiving the N data frames, that the system synchronization is abnormal when two pieces of system synchronization information in any two of the N data frames are identical. determining a lane for sending each of the N data frames according to the system synchronization information; and carrying and sending each of the N data frames in the determined lane; and wherein the synchronization method is characterized in that, the system synchronization is synchronization on the basis of the frame synchronization, and is configured to determine a transmission time delay, the system synchronization information is configured to directly or indirectly indicate predetermined time at which the N data frames reach the receiving end to enable the receiving end to determine, after receiving the N data frames, that the system synchronization is abnormal when two pieces of system synchronization information in any two of the N data frames are identical.