The Ti-6Al-4V polished by femtosecond laser processing is first investigated. The surface nanoparticles of Ti-6Al-4V induced by femtosecond laser have been characterized by scanning electron microscopy and energy dispersive spectrometry, and the influence of laser fluence and the overlapping rate of laser beam on surface roughness have also been analyzed. Moreover, the relationship between the laser parameters and the surface roughness of Ti-6Al-4V has been revealed, and the fine surface roughness of Ti-6Al-4V is obtained based on the optimized femtosecond laser processing parameters.