There are many holes used for assembly in carbon fiber reinforced plastic (CFRP) parts, traditional
hole-making method is subject to various damages such as delamination and fiber pullout. In this paper, drilling and
helical milling CFRP are carried out, according to comparison of the machining quality of two hole-making method,
the reason of the machining defect is analyzed. It was found that helical milling is a feasible method in hole-making,
which has a broad applied value in the CFRP hole-making technology.