A Hilbert-Huang Transform based on the high-frequency harmonic injection method (HF-HHT) is introduced to overcome the modal aliasing in empirical mode decomposition in the detection of transient disturbance signals in power systems. In this method, the frequency of the injected high-frequency signal is combined with HHT to analyze the transient disturbance signal, thereby achieving the purpose of suppressing modal aliasing. The key of HF-HHT is the selection of the high-frequency harmonic injection frequency. Through theoretical research and simulation experiments, an effective and universal frequency selection principle is obtained: HF-HHT is generally effective when the injected harmonic frequency is centered at 1/2 times the maximum frequency of the high frequency component of the original signal, and the up and down fluctuations are within 1/2 times the fundamental frequency. The analysis of the measured power quality signals proves the effectiveness and universality of the method in the detection of transient disturbance signals in power systems.