A data transmission method, including obtaining by a transmit end, at least two to-be-transmitted packets, determining a first interface used to transmit each of the packets in at least two interfaces of the transmit end, and determining an identifier of each of the packets that is related to the first interface, where the identifier represents an order of the first interface used to transmit each of the packets in the at least two interfaces used to send the at least two packets adding the identifier to a packet header of each of the packets and sending a packet added with the identifier to the receive end device through the first interface, so that the receive end device adjusts, based on the identifier, an order of the packet added with the identifier.