Relay link establishing method, site, and system

An embodiment of the invention relates to a relay link establishing method, receiving site, request site and system. In the method, the receiving site receives a first broadcast frame transmitted by the request site and a second broadcast frame transmitted by an access point; and when the first broadcast frame and the second broadcast frame are both relay discovery request frames of the request site and the receiving site is set as a relay site, a relay discover response frame is transmitted to the request site so that the request site can determine whether to establish a relay relation with the receiving site based on the relay discovery response frame. Thus, technical details that the request site transmits the Relay discovery request frames and receives the Relay discovery response frame are improved, the request site can transmit data to the AP by use of better channel conditions and a high-order MCS, the data transmission rate is improved, and the accuracy of data transmission is also ensured.