Abstract: In order to improve the quality of laser cutting aluminum alloy, an orthogonal test was carried out with laser power, cutting speed, defocusing amount and auxiliary gas pressure as the test factors, and the cutting seam width and cutting surface roughness as the quality characterization. The Taguchi method and variance method were used to analyze the influence of each test factor on the quality of the cutting specimen, and the optimal parameter combination of laser cutting aluminum alloy was determined. Through the verification test, it is concluded that the quality of aluminum alloy cut by the optimized parameters is more stable, the cutting seam width is smaller and the cutting precision is higher. The roughness of cutting surface is smaller and the cut surface is smoother.