Disclosed are a non-orthogonal multiple access (NOMA) multi-layer transmission method and an apparatus therefor. In the present disclosure, a terminal determines a spread spectrum sequence group for NOMA multi-layer transmission, with the terminal being configured for NOMA multi-layer transmission, wherein the spread spectrum sequence group includes N spread spectrum sequences, the N spread spectrum sequences correspond to N data layers, the N spread spectrum sequences are mutually orthogonal, N is the number of data layers of NOMA multi-layer transmission, and N is an integer greater than 1; and the terminal sends data, the data comprising the N data layers using the spread spectrum sequence group for spectrum spreading. After the terminal uses the spread spectrum sequences in the spread spectrum sequence group to carry out spectrum spreading on the N data layers, it can be ensured that the data layers, after undergoing spectrum spreading, are mutually orthogonal, such that the data transmission performance of the terminal can be improved.