This disclosure provides a sensing method. In the method, a first STA mainly controls a supplementary measurement of a first link between a second STA as a source node and the first STA as a destination node. When the first STA determines that the supplementary measurement needs to be performed on the first link, the first STA sends a first notification message to the second STA, to notify the second STA to initiate the supplementary measurement of the first link. Compared with a method in which an AP mainly controls the supplementary measurement of the first link, in this method, the first STA does not need to send a corresponding CSI measurement result to the AP after each measurement of a data packet of the second STA. This can reduce channel occupation during a sensing measurement, and further reduce interference caused by sensing to data communication.