Abstract: The LSD waves produced by irradiating aluminum targets in vacuum with a series of laser pulses have been studied numerically using the physical model of 1-D and two-temperatures for laser-target interactions. The relation between the pulse number ^N_LSD of LSDWs ignition and the normalized intensity (I₀/I_LSD) has been obtained for pulse duration t_p=10ns, and time gap between pulses t_r = 50ns. The accumulation effects of LSDWs ignition and shielding effects of LSD Ws have been analysed.