The present disclosure provides a data transmission method and device. The method includes: sending a first signal and a demodulation reference signal DMRS corresponding to the first signal to a second device; wherein the first signal includes at least one data stream, and each data stream corresponds to one DMRS port, one DMRS port corresponds to one or more of the following in different subbands: different power amplifiers, different sounding reference signal ports, or different first signal ports.