Abstract: In order to improve the ability of accurate early warning of optical fiber security system, Hilbert-Huang transform (HHT) technology was adopted to analyze the principle of optical fiber vibration sensor's signal. Time-frequency spectrums of different signals were obtained. The comparison of time-frequency spectrums of optical fiber vibration signals by HHT and continuous wavelet transform (CWT) was analyzed. The results show that HHT has an important value in time-frequency analysis of optical fiber security system.