Disclosed are a method for transmitting and receiving data in a wireless access system supporting relay nodes, and an apparatus for same. In particular, the present invention comprises: a broadcast phase for receiving an acknowledgement (ACK) signal from a first terminal and a negative acknowledgement (NACK) signal from a second terminal, after a base station transmits first data to the first terminal by using a first precoding vector (w1, B), and second data to the second terminal by using a second precoding vector (w2, B); a listening phase for receiving an ACK signal from the first terminal and a NACK signal from the second terminal, after the base station transmits second data to the first and second terminals by using a third precoding vector (wL); and a cooperative phase for the base station to transmit the second data to the second terminal, in cooperation with the first terminal, by using a fourth precoding vector (wC) which has been chosen for maximizing the transmission efficiency of the second terminal, wherein the first precoding vector, the second precoding vector, and the third precoding vector are chosen so that the total length of the rounds of all phases is minimized.