Abstract: For extraction the no-load voltage harmonic parameters feature of a special vehicles generator, an adaptive algorithm based on LMS was proposed with high analysis precision. The establishment of this type of generator no-load phase voltage harmonic analysis of the adaptive linear combiner model, the model is given in combination with adaptive methods of harmonic analysis of the theoretical derivation and implementation steps. Simulation and practical application results show that except for high accuracy, the proposed method is easy to be realized and can fulfill the requirements of generator fault feature extraction.