Embodiments of this application provide an access point (AP) multi-link device discovery method and a related apparatus, for example, in a wireless local area network (WLAN) supporting IEEE 802.11be. In an example method, a reporting AP sends a first management frame to a station. The first management frame carries information about a reported AP. The reporting AP is affiliated with an AP multi-link device. The reported AP is affiliated with the same multi-link device as the reporting AP. Or the reported AP belongs to a same multiple basic service set identifier (BSSID) set as another AP in the multi-link device with which the reporting AP is affiliated.