Lamb wave is widely used for damage detection of laminated structure.The dispersion characteristic of Lamb wave complicates the signal analysis procedure and this phenomena also brings difficulties in characteristic parameter extraction during damage detection.It is necessary to use a suitable time-frequency domain conversion method for the Lamb wave. Firstly， the propagation property and generation mode of Lamb are presented. Then Hilbert-Huang Transform (HHT) is introduced in detail in order to extract the Hilbert spectrum， instantaneous energy density spectrum and marginal spectrum of Lamb wave signal by Matlab. Finally， HHT is used to analyze the signals which are collected in the experiment before and after damage in order to extract characteristic parameter about energy and time. The experiment results and comparative analysis show that HHT is suitable to extract the energy attenuation and time delay information of the signal before and after the damage， which provides the data basis for the next step to identify the damage degree and location.