A data transmission method and a data transmission device are provided. A transmission device classifies data symbols for each scheduled user into groups based on logic resource element groups determined based on encoding matrices each multiplexed by multiple users, encodes respective groups of data symbols for each user in accordance with the encoding matrices to determine groups of encoded data symbols for each user, subjects respective groups of encoded data symbols for each user to a mapping treatment based on logic resource elements, maps respective logic resource element groups to a physical resource block in accordance with a mapping mode, and transmits data to a reception device based on the physical resource block.