Using rhizome of processed Rhizoma atractylodis as experimental material, the yield of polysaccharide from rhizome of processed Rhizoma atractylodis was determined by modified phenol-sulfuric acid method. Single factor analysis was used to investigate the different liquid-solid ratio, extraction temperature, extraction time and extraction times. The change of polysaccharide yield was detected and the best level was selected. Response surface methodology was used to optimize the extraction process, and the optimal extraction process was obtained.The results showed that the yield of polysaccharide from rhizome of processed Rhizoma atractylodis could reach 3.65% when the ratio of liquid-solid was 25∶1, the extraction temperature was 89℃, the extraction time was 68min. The research provides a theoretical basis for further development and utilization of rhizome of processed Rhizoma atractylodis.