Embodiments of this application provide data transmission methods and apparatuses. One method includes: receiving, by a communications apparatus, indication information from a network device, wherein the indication information indicates a data distribution selected from a first data distribution and a second data distribution; performing, by the communications apparatus, data transmission with the network device based on the data distribution; wherein the data distribution indicates a distribution of modulation symbols of a code block (CB) on one or more orthogonal frequency division multiplexing (OFDM) symbols of at least one resource unit, and wherein the one or more OFDM symbols are consecutive in time-domain.