Various embodiments provide a data communication method. Under the method, a transmit end maps each code block group CBG in N CBGs to each layer in a corresponding layer group based on a correspondence between the N CBGs and N layer groups. Each layer group includes at least one layer, and N is a positive integer. The transmit end then sends data to a receive end. T transport block corresponding to the data includes the N CBGs. In this way, a mapping relationship between a CBG and a layer group is established by grouping layers, so as to improve data reception quality, through interference cancellation, for transmission among different layer groups, and ensure adaptivity to a CBG-based retransmission feedback, thereby optimizing transmission performance of an entire communications system.