A data transmission method, executed by a base station on the basis of a non-orthogonal mode, to improve data transmission capability of a communication system comprising the base station and a plurality of User Equipments, UEs, comprising steps of: mapping a plurality of pieces of data to physical resources, each piece of data in the plurality of pieces of data being mapped to at least one physical resource,; and transmitting to the plurality of UEs the plurality of pieces of data on the physical resources, wherein the number of the physical resources on which the pieces of data are transmitted is not greater than the number of the pieces of data to improve data transmission capability for a communication system, the number of the pieces of data mapped to each physical resource is not greater than the number of the physical resources, the pieces of data mapped to an identical physical resource are linearly superposed and then transmitted on the physical resource, the plurality of pieces of data is divided into a plurality of multiplexing layers, and the number of the physical resources to which each piece of data in a previous multiplexing layer is mapped is greater than the number of the physical resources to which each piece of data in a current multiplexing layer is mapped, wherein the number of the physical resources to which each piece of data in the same multiplexing layer is mapped is the same, wherein the pieces of data which are in the same multiplexing layers and belong to different users are overlapped to the minimum degree; characterized in that, the data transmission method further comprises steps of: subjecting the multiplexing layers of an identical type which have an identical equivalent spreading factor to interference minimization treatment, wherein the multiplexing layers are determined to be of an identical type according to their spreading matrices. mapping a plurality of pieces of data to physical resources, each piece of data in the plurality of pieces of data being mapped to at least one physical resource,; and transmitting to the plurality of UEs the plurality of pieces of data on the physical resources, wherein the number of the physical resources on which the pieces of data are transmitted is not greater than the number of the pieces of data to improve data transmission capability for a communication system, the number of the pieces of data mapped to each physical resource is not greater than the number of the physical resources, the pieces of data mapped to an identical physical resource are linearly superposed and then transmitted on the physical resource, the plurality of pieces of data is divided into a plurality of multiplexing layers, and the number of the physical resources to which each piece of data in a previous multiplexing layer is mapped is greater than the number of the physical resources to which each piece of data in a current multiplexing layer is mapped, wherein the number of the physical resources to which each piece of data in the same multiplexing layer is mapped is the same, wherein the pieces of data which are in the same multiplexing layers and belong to different users are overlapped to the minimum degree; characterized in that, the data transmission method further comprises steps of: subjecting the multiplexing layers of an identical type which have an identical equivalent spreading factor to interference minimization treatment, wherein the multiplexing layers are determined to be of an identical type according to their spreading matrices.