Aiming at the problem of too many rotary angles leading to low calibration efficiency during the on-machine measurement of group holes,a clustering-based method of rotary angle planning for group holes was proposed.The angle threshold between the stylus axis and the hole axis was calculated under the constraint of avoiding the interference between the stylus and the hole,and then iterative clustering was performed with this threshold as the boundary condition,the set of rotary angles were obtained,which can measure all group holes without interference.The results show that the proposed method can realize the rotary angle planning for the group holes rapidly,the number of rotary angles reduce by 28% and overall measurement time reduce by 19% compared with the traditional method,which improves the efficiency of the on-machine measurement of group holes.