Abstract: In order to acquire the high power laser pulse sequence to increase the quality of laser drilling and thin the recast layer of micropores, a system is designed to make acousto-optic modulation(AOM) on the Nd: YAG pulse laser by a certain shape of external trigger signal so that the laser pulse sequence of the high power of 2.5×10² kW is obtained. The modulation signal of different external trigger waveform and the laser pulse sequence shape under different delay time(50-250μs) are studied. According to the circuit of charge and discharge and the time of electro-optic transfer, the influence of delay on pulse sequence is analyzed, and from this it is known that the delay time of the AOM of Nd: YAG pulse laser is about 150μs.