Aramid fiber-reinforced polymer was easy to occur defects such as ablation and burr in traditional turning process. The method of liquid nitrogen cooling turning process was carried out to reduce the defects of fluff and high temperature ablation of aramid fiber material and improve the cutting performance and machining quality. The experimental results of dry turning and liquid nitrogen cooling turning of materials were analyzed,and the mechanism of liquid nitrogen low temperature turning was discussed.The results show that with the increase of spindle speed, the fiber surface quality is improved.Especially at 1 340 r/min,the optimum surface is obtained.In liquid nitrogen cooling turning process with different speeds,surface qualitis are better.At the same spindle speed,the surface quality of liquid nitrogen cooling turning is better than that of dry turning.Therefore，the decreasing cutting temperature has played a positive role for the improvement of the aramid fiber cutting defects.