A packet transmission method, packet transmission apparatus, and an interconnect interface are presented, where the method includes determining, by a sending node, whether an unrecoverable failure occurs in an active link, and if an unrecoverable failure occurs in the active link, selecting, from multiple communication links, at least one standby link except the active link to send a packet to a receiving node, so that the receiving node sends the packet to a receive end of the active link. In the method, for two nodes in an interconnect system that communicate with each other using multiple Links, when it is determined that an unrecoverable failure occurs in some of the Links, packets in retransmission buffers of transmit ends of the links in which the failure is unrecoverable are sent to a standby link.