A method in the field of networking technologies for sending a wake up packet, an apparatus, and a device. The method for sending a wake up packet is applied to a first node, wherein the first node maintains a first contention window (CW1) on a first channel, the first channel is a channel on which a main transceiver of a second node works, and the method includes generating a backoff count based on CW1, executing backoff based on the backoff count, and sending a wake up packet to the second node on a second channel when backoff ends, wherein the second channel is a channel on which a wake up receiver of the second node works.