<p>Compared to meta-aramid honeycombs (MAHs), para-aramid honeycombs (PAHs) exhibit superior mechanical and physical properties and can therefore be used in more demanding environments. However, the excellent properties of PAH also bring great challenges to the traditional machining methods, often resulting in terms of large burrs, delamination, tearing, and cell collapse of the honeycomb, as well as severe tool wear problems. These challenges severely limit the application of the PAH. Therefore, investigating effective machining methods for PAH and optimizing the machining quality by determining the influence laws of the process parameters are crucial. In this paper, series of single factor orthogonal experiments were performed to study the effects of machining parameters on ultrasonic cutting characteristics between PAH and MAH in terms of cutting force, cutting temperature and surface quality by disc cutter. Furthermore, this study compared the microscopic ultrasonic cutting processes of PAH and MAH, analyzed the impact of aramid fiber differences on the honeycomb walls fracture process, and revealed the reasons for the differences in experimental results between PAH and MAH. Results proved that PAH exhibited poorer cutting performance compared to MAH: the cutting force and cutting temperature of PAH were both higher than those of MAH, and the machined surface was rougher. The processed surface damage of PAH predominantly manifests as clusters of long uncut fibers, whereas MAH is mostly short burrs. Increasing the ultrasonic amplitude can reduce the cutting forces for PAH and MAH, with a particularly greater reduction in force for PAH. The present study can be used as basis for comprehensive understanding of the differences in the cutting performance and mechanisms of PAH and MAH and optimization of machining parameters for ultrasonic cutting by disc cutter.</p>