In this study, the effects of process parameters such as power, filling intervals and repetition rate on the surface roughness of aluminum alloy (2024) were studied in order to analyze the law of influence between process parameters and roughness from the aspects of morphology and product composition. Firstly, 1 060 nm MOPA laser was used to mark aluminum alloy 2024, and then the surface roughness of the mark was measured by roughness detector under different process parameters, and the results show that power, filling interval and repetition rate affect the melting, gasification and recasting degree of the material surface, resulting in different surface roughness and different roughness variation rules. The surface morphology of the marking area was observed by digital microscope system, and the chemical composition of the marking area surface was analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results show that the melting, vaporization and recasting degree of the marking area surface are obviously different with different process parameters, so the surface morphology and products affect the surface roughness of the marking area.