In this paper, a three-temperature heat transfer model was developed based on the temperature transfer process in the femtosecond laser scanning processing of the face gear material 18Cr2Ni4WA, and a multi-pulse energy accumulation model in the scanning process was established. The simulation analyzed the changes of electron lattice temperature when changing the laser energy density on the ablated material, the changes of maximum temperature of electron, lattice and material surface under multi-pulse loading, and the changes of loading energy when changing the scanning speed and scanning interval, and concluded that with the increase of energy density, the maximum temperature of electron increased from 37000 K to 44000 K, and the final equilibrium temperature increased from 17000 K to 22000 K. Under multi-pulse loading, with the increase of energy density, the maximum temperature of electrons also increases to a certain extent, and the equilibrium temperature of the highest temperature of the material surface also increases, from 2600 K to 3250 K. With the increase of scanning speed and scanning interval, the accumulated energy of multi-pulse has a certain decrease, and the energy distribution scale is increasing. The experiments analyzed the effects of different energy densities, scanning speeds, and scanning intervals on the femtosecond laser ablated surface gear material, and the roughness analysis of the ablated morphology was carried out, and it was concluded that the quality of the ablated morphology was better when the energy density was 4.34 J/cm², the scanning speed was 300 mm/s, and the scanning interval was 18 μm. These provide a research basis for improving the surface morphology quality of the surface gear materials processed by femtosecond laser scanning.