The invention provides a data processing method for an interleave division multiple-access (IDMA) transmitter system, an interleave division multiplexing transmitter and a transmitter. The IDMA transmitter system mainly comprises a plurality of transmitters, each of which comprises inserted prefix units and interleavers; each transmitter is identified according to the difference of the interleavers; no IFFT unit with a same mapping mode is arranged between the interleaver and the inserted prefix unit of each transmitter. By utilizing the method of the invention, the complexity of the IDMA system is effectively reduced and the system has the advantages of comparatively low peak-to-average ratio and the insensitivity to frequency deviation, etc.