Provided are a data retransmission method and a communication device. The data retransmission method comprises: sending, by a transmitting end device, a first data set to a receiving end device using a first transmitting mode set; and retransmitting, by the transmitting end device, the first data set to the receiving end device using a second transmitting mode set, so that the receiving end device merges the first data set sent by the transmitting end device using the first transmitting mode set with the first data set retransmitted using the second transmitting mode set and demodulates the first data set, the transmitting modes in the first transmitting mode set and the transmitting modes in the second transmitting mode set being orthogonal in one-to-one correspondence or being quasi-orthogonal. The data retransmission method and communication device provided in the embodiments of the present invention are used for improving the performance of data retransmission.