The laser direct marking of Aluminum alloy (2024) was carried out on 1060nm MOPA laser. The quality grade and contrast of DM codes at different power levels were studied. The surface morphology of the marking was observed by scanning electron microscopy (SEM), and the composition of the marking surface was analyzed by energy dispersive spectrometer (EDS). Through SEM analysis, it was found that the marking surface material with good quality level of DM code is melted, vaporized and ablated, with a large number of holes and granular substances, while the marking surface material with poor quality grade of DM code is only recast and the surface is wavy; EDS analysis shows that the content of oxygen elements in the marking surface materials with higher DM code quality grade increases, indicating that the melted and vaporized metals undergo oxidation reaction, while the amount of oxygen elements on the marking surface with lower DM code quality grade increases less, indicating that the metal oxidation reaction is less under this condition. In this paper, the ablative threshold of the material is calculated to provide theoretical guidance for the test.