Abstract: The specific experimnt of femtosecond laser processing stainless steel was carried out.By setting different process parameters, the influence law of different variables on various indexes of surface microstructure in single factor experiment is studied, and its formation mechanism is analyzed and summarized; The orthogonal experiment was further designed, the matrix array structures with different morphologies were obtained by changing the process parameters, the comprehensive surface processing under multiple factors was studied, and the effects of various factors on the depth, width and roughness of microstructure were summarized; The range analysis of the results is carried out to determine the most influential processing factors, and the optimal processing level within the set parameters is obtained.