The invention relates to a method for selecting a wireless relay node for a multi-relay system multiflow unicast mode, which comprises the following steps: before a system carries out unicast transmission, all relay nodes to be selected respectively feed back part of channel information of a relevant channel to a source node so as to replace a method for feeding back all real-time channel information in the prior art and greatly save the transmission cost of a feedback signaling; after obtaining the information, the source node selects an optimal relay node to carry out unicast transmission according to a calculation way of the volume of the system; simultaneously, all relay nodes update feedback channel information to the source node in a set period in the process so as to carry out nextrelay selection; the source node selects the relay node when the next relay selection starts according to the same way and also informs the selected relay node by the signaling, and the unselected relay node continuously maintains a ready state. The invention not only can obtain the system volume performance compared with the feedback real-time channel information, but also can greatly save the transmission cost of the feedback signaling.