A data transmission method, comprising: receiving, by a receiving device, first data on a first time-frequency resource, and receiving second data on a second time-frequency resource; and when the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, using, by the receiving device, 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, wherein the using, by the receiving device, a first DMRS to demodulate the second data mapped to a target frequency domain resource of the second time-frequency resource comprises: when a spacing satisfies a relationship with a preset spacing, and the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, using, by the receiving device, the first DMRS to demodulate the second data mapped to the target frequency domain resource of the second time-frequency resource, wherein the spacing is a spacing between the first time-frequency resource and the second time-frequency resource, and wherein the preset spacing is determined based on a moving speed of the terminal device and a channel time variant parameter of the terminal device. receiving, by a receiving device, first data on a first time-frequency resource, and receiving second data on a second time-frequency resource; and when the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, using, by the receiving device, 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, wherein the using, by the receiving device, a first DMRS to demodulate the second data mapped to a target frequency domain resource of the second time-frequency resource comprises: when a spacing satisfies a relationship with a preset spacing, and the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, using, by the receiving device, the first DMRS to demodulate the second data mapped to the target frequency domain resource of the second time-frequency resource, wherein the spacing is a spacing between the first time-frequency resource and the second time-frequency resource, and wherein the preset spacing is determined based on a moving speed of the terminal device and a channel time variant parameter of the terminal device. when a spacing satisfies a relationship with a preset spacing, and the first time-frequency resource and the second time-frequency resource have an overlapped target frequency domain resource in frequency domain, using, by the receiving device, the first DMRS to demodulate the second data mapped to the target frequency domain resource of the second time-frequency resource, wherein the spacing is a spacing between the first time-frequency resource and the second time-frequency resource, and wherein the preset spacing is determined based on a moving speed of the terminal device and a channel time variant parameter of the terminal device.