Embodiments of the present invention disclose a multi-link aggregation method, including: establishing, by a first device, a transparent transmission channel with a second device, where the transparent transmission channel spans multiple links connected to the first device and the second device; performing, by the first device, network address translation on a first target packet to obtain a second target packet; and transmitting, by the first device, the second target packet to the second device through the transparent transmission channel, so that the second device performs network address translation on the second target packet to obtain a third target packet, and the second device sends the third target packet to a target device identified by destination address information of the first target packet.