Abstract: Carbon fiber-reinforced plastic (CFRP) composites have been widely used in aerospace and other most advanced fields. It is difficult to avoid voids and other defects in the manufacturing process of CFRP, which will have a certain impact on the subsequent machining. Based on the consideration of the voids defects in the process of CFRP forming, a CFRP micro cutting simulation model with void defects was established from the fiber-resin-interface scale by using the finite element simulation method. The micro cutting behavior of CFRP with different fiber orientations under different void content conditions was studied, and the correctness of the simulation model was verified by experiments. The results show that the existence of voids will increase the ‘virtual cutting’ phenomenon of the tool, which will have an impact on the cutting force, material damage, sub-surface damage and material energy in the cutting process of CFRP. The cutting force decreases with the increase of void content, and the tendency of fibers at the edge of voids to produce overall fracture will increase. The voids have little effect on the damage under the machined surface of CFRP with 0°, 45° and 135° fiber orientations. The void content higher than 3vol% has a great effect on the damage under the machined surface when the fiber orientation is 90°. In terms of energy dissipation inside the material, the total dissipated energy in ‘forward cut’ (fiber orientation angle less than 90°) is lower than ‘reverse cut’, furthermore, the total dissipated energy decreases with the increase of void content.