Abstract: The propagation of Lamb wave in a composite panel was modeled based on the spectral finite element (SFE). Combined with Gabor wavelet analysis, the simulated results obtained by the SFE and by the classical finite element method (FEM) were compared to the theoretical result. The scanning process of the Phased Array damage detection was simulated by the SFE, and the propagation and scanning images of Lamb wave were presented. The results show that besides getting more accurate results, the SFE is able to immensely save computing time compared with the classical FEM. Thus, the advantage of the SFE in modeling the Lamb wave propagation in composite panels is verified. The results also show that the SFE method can accurately simulate the scanning process of the Phased Array damage detection. The coincidence of the simulated results with the actual situation verifies the feasibility and veracity of the present modeling method.