A method of etching micro-grating structures (MGSs) by ablating chrome film on glass was investigated,which was used the interference laser of 351 nm diode-pumped solid-state laser (DPSSL) pulses.Through changing the experimental parameters such as laser power,number of laser pulses，the influences of these parameters on the depth of grooves and diffraction efficiency of MGSs were analyzed.Measured by conventional optical microscopy and atomic force microscopy (AFM),the highest depth of MGSs is 1.01 μm.The first-order diffraction efficiency of the MGSs was measured using 532 nm laser,and the highest of witch was 6.5%.The experimental results show that increasing the number of laser pulses properly in prpper laser energy,the depth of grooves and diffraction efficiency are increased.