This paper is mainly about the micro-nano structure on stainless steel surface was fabricated by picosecond laser under the static experimental condition, and the surface morphology after ablation is observed and measured by laser scanning confocal microscope (LSCM) and scanning electron microscope(SEM). The technological disciplinarian of stainless steel ablation with different laser parameters, such as power percentage and processing times, was studied. The results show that the change of average power has a main influence on the energy density of laser pulse. With the increase of average power, the energy density of single pulse raises linearly, and the ablation rate increases exponentially. At the same time, the width and depth of micro-nano structures rises with the increase of average power, and the multiscale structure improves gradually. And change the number of processing mainly affects the laser pulse number, the pulse numbers increase linearly with the improve of the processing times. When processing times increase gradually, the width of the micro-nano structures remains the same and then increases and eventually keeps it steady; the depth raises firstly, then decreases, and continues growing finally, while the ablation rate decreases with the power function.