The invention discloses a data transmission method. The method comprises the following steps: dividing a to-be-sent data symbol into data symbol segments and numbering the data symbol segments; performing windowing and FFT processing on each data symbol segment according to the serial number of the data symbol segment; according to the serial numbers of the data symbol segments, respectively carrying out real-virtual staggered extraction on each processed data segment; carrying out up-sampling and filtering on the output of each FFT frequency point, carrying out D/A on a filtering result, andsuperposing the filtering result into an intermediate frequency sending signal; after up-conversion is carried out on the intermediate frequency sending signal, the signal is sent through a power amplifier. According to the invention, serial-parallel conversion is carried out, the data rate of each sub-signal is 1/N times of that of input data; carrying out K times of up-sampling; the data rate ofeach sub-signal is K/N times of that of input data. Digital-to-analog conversion D/A is performed on each FFT frequency point, and the D/A converter is converted into a plurality of D/A converters, so that the sampling rate of the D/A converter on each sub-signal is reduced to K/N times of input data, and the cost of the D/A converter and the cost of the A/D converter are greatly reduced.