The invention discloses a reliable data transmission method for a virtual network link. The method solves the problem that in the prior art, transmission reliability of virtual network data still needs to be improved. Data transmission completed by a virtual link sending end includes the following steps that firstly, all disjoint paths between virtual link end points are calculated at the virtual link sending end; secondly, the obtained shortest path is set as a standby path, and other paths serve as main paths; thirdly, each data message to be sent in the virtual link is segmented into k equal parts, and k is the number of the main paths; fourthly, sub data messages of each part are transmitted along the corresponding main path; fifthly, xor operation results of all the sub data messages form a standby data message which is transmitted along the standby path. Segmentation and xor operation are carried out on the original data messages, so that standby data are compressed, resource consumption of the standby path is reduced, and quick restoration of faults is guaranteed.