The invention discloses a method for obtaining harmonic parameters on the basis of a clonal selection algorithm and improved fast S transformation. The method comprises the following steps that signals are subjected to improved fast S transformation; the number, the frequency, the amplitude value and the phase parameter of harmonic ingredients in the tested signals can be obtained according to a result matrix of the improved fast S transformation; the result matrix of the improved fast S transformation is subjected to linear decomposition; the reverse fast S transformation is used for rebuilding a time domain waveform of each harmonic ingredient; the detected frequency value of each harmonic ingredient is modified; a time domain model of each harmonic ingredient in the tested signals is built according to the detection information; the detected amplitude value and the phase information of the harmonic ingredients are corrected by using the clonal selection algorithm. The clonal selection algorithm and the improved fast S transformation algorithm are adopted, the advantages of high detection precision, high convergence rate, high searching capability and the like are realized, and various parameters in the harmonic ingredients can be extracted from complicated distortion signals.