The invention relates to a tune energy and human ear frequency selectivity based squeal judgment method for speed reducers/changers. The method comprises the steps: firstly, sampling noise signals ofa speed reducer/changer, carrying out A weighting on the noise signals, converting processed signals to log domains, and carrying out Fourier transformation, so as to obtain energy-amplitude frequencycurves; then, calculating feature loudness and critical band rate of the noise signals, calculating frequency band acuity of each feature loudness, and subjecting frequency band acuity to normalizingtreatment; subjecting the energy-amplitude frequency curves to frequency interval Gauss smoothing processing to obtain background noises, and selecting candidate tunes; calculating a frequency band acuity weighting factor according to a corresponding relationship between the critical band rate and frequency, and carrying out weighting, so as to obtain the energy-amplitude frequency curves of thenoise signals; calculating tune energy in bandwidth of the tunes, background noise energy and difference between the tune energy and the background noise energy, and carrying out primary and secondarysequencing on abnormal noise frequencies affecting squeal. According to the method, a low-frequency region becomes a non-sensitive region, and a high-frequency region highlights acuity attribute, andthus, a subjective sensation of human ears to squeal is effectively simulated.