This paper studies the fatigue enhancement mechanism of the super-Gaussian amplitude distributioncharacteristic. At first it is demonstrated that the responsestressesamplitudedistribution is super-Gaussian in the repetitiveshockmachine. Then it isproved that the super-Gaussianrandom stressed have higher efficiency to stimulate fatigue failure than Gaussian random stresses of the equivalent lever. Finally the fatigue enhancement mechanism of super-Gaussianamplitude distribution characteristic is illustrated.