Abstract: In order to improve the machining efficiency of the tail wing of high speed aircraft, the laser cutting technology was used instead of the traditional WEDM process. The laser cutting experiments of the tail wing were carried out under different parameter combinations with Q235 steel plate with different thickness as the cutting object. The effects of laser cutting speed v and oxygen assisted pressure P on the surface roughness and surface morphology of the tail wing were studied, and the effects of the above process parameters on the cutting quality of the tail wing with different thickness were obtained. The results show that the surface quality of cutting seam increases at first and then decreases with the increase of cutting speed and auxiliary air pressure. With the increase of steel plate thickness, the optimum cutting speed becomes smaller, the auxiliary air pressure does not change obviously, and the adjustable range of processing parameters becomes smaller.