The invention discloses a transmitting antenna selection method for a generalized spatial modulation system based on a channel capacity optimized (CO) criterion. A transmitting end introduces an antenna selection module based on the channel capacity optimized criterion, and performs antenna selection according to channel state information of a GSM-MIMO system. According to the method, firstly, channel columns corresponding to each activated antenna combination are added; secondly, channel capacity under each antenna selection scheme is calculated; and finally, the antenna selection scheme with the maximum channel capacity is selected as a final antenna selection result. According to the method, the bit error rate performance of the generalized spatial modulation system is improved, and the method has relatively low computing complexity.