Embodiments of this application provide a probe request and response technology between a station and a plurality of AP MLDs. If the station wants to obtain a communication parameter of a nontransmitted BSSID AP, the station may send a probe request frame to a nontransmitted BSSID AP in an MBSSID set, and a transmitted BSSID AP in the MBSSID set may reply with a probe response frame. Alternatively, if the station wants to probe a plurality of AP MLDs at a time, the station may send the probe request frame to one transmitted BSSID AP in the MBSSID set, to request the AP to reply with a communication parameter of the nontransmitted BSSID AP. The nontransmitted BSSID AP and the transmitted BSSID AP may belong to different AP MLDs. During implementation of this application, a station may obtain communication parameters of a plurality of APs of one or more AP MLDs by sending one probe request frame, to obtain communication parameters of the AP MLD on a plurality of links, thereby efficiently implementing association between the station and the AP MLD or establishing multi-link transmission between the station and the AP MLD.