采用四因素四水平的田口正交阵列法，在厚度为3 mm的高温合金上进行了Nd∶YAG激光脉冲环切打孔实验，分析了脉冲能量、离焦量、环切圈数及环切速度对小孔锥度和圆度的影响，并对工艺参数进行了优化，得到了最小的微孔锥度和较好的微孔圆度。结果表明,激光环切打孔时，脉冲能量、离焦量、环切圈数和环切速度对微孔圆度影响不大，但离焦量对微孔锥度影响最大；得到最小孔锥度所用的最佳工艺参数组合为：环切圈数6，环切速度6 mm/min，脉冲能量1.5 J，离焦量-0.5 mm；孔出口处的圆度比孔入口处的圆度好。

The Taguchi′s orthogonal array method with four factors and four levels is used to carry out the experimental investigation of the Nd∶YAG pulsed laser trepanning drilling of the superalloys with the thickness of 3 mm. The influences of pulse energy, defocusing amount, number of trepanning and trepanning speed on hole taper and hole circularity are analyzed. The laser processing parameters are also optimized and the minimum microhole taper and the relatively better microhole circularity are obtained. The results show that the influences of pulse energy, defocusing amount, number of trepanning, and trepanning speed on microhole circularity are not significant during the laser trepanning drilling process, while the influence of defocusing amount on microhole taper is the most. Moreover, the minimum microhole taper is obtained when using the optimal laser processing parameters as the number of trepanning of 6, trepanning speed of 6 mm/min, pulse energy of 1.5 J, and defocusing amount of -0.5 mm. In addition, the hole circularity at exit is better than that at entry.