A nanosecond pulse laser was used to conduct laser cleaning experiments on the oxide after welding of 6061 aluminum alloy. By analyzing the three-dimensional morphology and elemental structure of the surface before and after cleaning, the composition of oxide after welding can be determined; Based on the research on the influence of different process parameters on cleaning quality obtained from previous experiments, the interval range of each process parameter is defined, and orthogonal experiments are conducted on four factors to analyze the weight of each parameter"s impact on cleaning quality. By using the orthogonal experimental method, it was found that the order of parameters affecting the peak valley values of surface contour lines is: laser power>pulse frequency>scanning speed>pulse width; The order of parameters that affect the weight percentage of O element is: pulse width>scanning speed>laser power>pulse frequency. The optimal process parameter group was obtained through the comprehensive balance method: scanning speed, laser power, pulse frequency, and pulse width were 2950mm/s, 141W, 29kHz, and 330ns, respectively. The optimal parameters can ensure thorough oxide cleaning, no substrate damage, and high cleaning efficiency of aluminum alloy after welding.