The invention provides a data transmission method and device. The method comprises the steps that network equipment determines a plurality of precoding matrixes adopted by terminal equipment for sending uplink data on a plurality of sub-bands, the plurality of sub-bands and the plurality of precoding matrixes are in one-to-one correspondence, and the terminal equipment is any one of a plurality ofpieces of terminal equipment for MIMO transmission; the network equipment compresses the plurality of pre-coding matrixes to obtain compressed pre-coding matrix information; and the network device sends the precoding matrix information to a terminal device. According to the embodiment of the invention, the terminal equipment can adopt a more accurate pre-coding matrix to carry out uplink MIMO coding, so that the system performance can be improved.