The present invention relates to a method by which a terminal transmits a signal in a wireless communication system supporting multiple-input multiple-output (MIMO), and to a device. Particularly, the method comprises the steps of: transmitting a scheduling request to a base station by using a scheduling request beam resource, and receiving, from the base station, a confirm message corresponding to the scheduling request, wherein the confirm message includes an indication determined according to the scheduling request beam resource and the best downlink beam preset to a terminal.