Abstract: When Q-switched Nd:YAG laser radiation goes through a LiIO3 crystal,the stress wave will be induced for the laser radiation weak absorption of the crystal.In SHG of 1064nm laser radiation,the stress wave are enhanced and vary with the variation of phase mismatching angle.In this process,there exist the 1064nm fundamental laser radiation and 532nm SHG radiation in LiIO3 crystal,and the absorption to 532nm laser radiation is more serious than to 1064nm laser radiation.