The surface morphology of the ablation region of femtosecond laser finishing surface gear material 18Cr2Ni4WA is directly related to the laser process parameters. In order to obtain a better surface topography of the ablation region, a three-factor, three-level orthogonal test is designed, and the effects of laser repetition frequency, energy density and scanning speed on the depth of the ablation region and surface roughness are analyzed by signal-to-noise ratio, and the optimal combination of process parameters is obtained with a single response target. Combining the grey correlation method to optimize the two response targets, the optimal process parameter combinations are obtained as 200 kHz repetition frequency, 3.5 J/cm² energy density, and 110 mm/s scanning speed, and the optimal process parameter validation test shows that the optimized surface topography has a better overall quality, which proves the reliability of the grey correlation method of multi-response optimization, and provides a method to improve the quality of surface topography for the femtosecond laser micromachined face gears. This proves the reliability of the grey correlation method and provides an effective method to improve the surface topography of femtosecond laser micromachined gears.