Embodiments of this application provide example data transmission methods. One example method includes: receiving, by a receiving device, first data on a first time-frequency resource, and receiving second data on a second time-frequency resource. When the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, the receiving device can then use a first DMRS mapped to a target frequency domain resource of the first time-frequency resource to demodulate the second data mapped to a target frequency domain resource of the second time-frequency resource.