The invention provides a method for generating digital modulating signal waveform data by an AWG, and aims at disclosing a digital modulating signal waveform data generation method which is capable of generating stable and low-distortion output signals, keeping the continuity and integrity of signal waveform files and not causing phase jump during cyclic reading. The method is realized through the following steps of: selecting a combination of a carrier center frequency f0, a symbol rate Rs and a code element number L, which satisfy any waveform parameter at the same time; when a sampling rate fs of the waveform files satisfies a Nyquist sampling rate theorem and is not higher than a DAC highest working frequency and the sizes of the a waveform files satisfy a storage capacity, searching an optimum sampling total time length Ttotal and fs to ensure that a generated actual carrier center frequency f'0 approaches to f0 in the aspect of waveform; and cyclically searching a sampling total time, the sampling rate and a finely tuned carrier center frequency parameter, solving an optimum waveform parameter, and generating signal waveform files which are connected end to end and do not cause phase jump during cyclic reading.