Abstract: The effects of the parameters of laser and aluminium plate on laser-induced Lamb waves in aluminium plates are analyzed by using finite element method. Through the establishment of axis-symmetry laser radiation model, transient temperature field distribution under different laser energy is calculated. Research results show that surface material will be damaged when the laser energy is too high. Therefore, laser energy should be controlled to be lower than material damage threshold value. While laser energy is fixed, plate thickness and laser beam radius are changed, it is found that excitation rate of Lamb waves increases and signal spectra band broadens and spectral component becomes richer when laser beam radius decreases.