Phase correction and nonuniform phase amplitude conversion method and device in DDS

The invention discloses a phase correction and nonuniform phase amplitude conversion method and device in DDS. The method includes that a phase accumulator receives a frequency control word and outputs a phase value without accuracy loss; a phase comparator receives the phase value, processes the same and outputs a quadrant value of the phase value to acquire an inquiry address of ROM in a phase amplitude converter; the phase amplitude converter utilizes the inquiry address to find an amplitude value corresponding to the phase value and stored in own ROM, utilizes the quadrant value to perform symbol modifying on the amplitude value and outputs the amplitude value after being modified, wherein the amplitude value stored in storage space of ROM is nonuniform; a digital analog converter performs digital analog conversion on the modified value and outputs an analog signal value; a low-pass filter performs low-pass filtering on the analog signal value and outputs an analog triangular function signal. By the phase correction and nonuniform phase amplitude conversion method and device, the problem that output waveforms are seriously stray in existing DDS designing is solved, and designing difficulty and cost expense are lowered.