It is crucial to investigate the mechanism of ultrashort pulse laser processing of ZrO₂ ceramics to improve its processing accuracy and efficiency. An ultrashort pulse laser was used to fabricate square grooves on the surface of ZrO₂ ceramics. The depth, surface roughness, and surface topography of grooves were analyzed by the laser confocal microscope, optical profiler, and scanning electron microscope. The effects of different laser parameters on the material removal efficiency and processing quality of ZrO₂ ceramics were studied. The results show that as the laser fluence increases, material removal efficiency first increases and then decreases, while the surface roughness first decreases and then increases. The heat accumulation effect is severe when using high repetition frequency, and the processed surface shows melt damage. As the pulse width increases from 390fs to 6ps, the ablation threshold increases from 1.28 J/cm² to 1.92 J/cm². However, the material removal efficiency decreases gradually. Furthermore, the material removal efficiency in burst mode significantly reduces due to the plasma shielding and redeposition of distinct granular deposits within the grooves. These findings can serve as a guide for controlling and optimizing the process parameters of an ultrashort pulse laser processing of ZrO₂ ceramics

Keywords: Ultrashort pulse laser, Laser processing, ZrO₂ ceramics, Surface roughness, Removal efficiency