[Objective] To improve the production efficiency of the oligosaccharide industry. [Methods] Isomaltooligosaccharides 50 syrup was used as the raw material, and purified by sequential simulated moving bed chromatography. Potassium ion resin was selected as the suitable separation medium by preparative chromatography single column experiment. Then, based onthe principle of material balance and the basic principle of sequential simulated moving bed, the initial operating parameters of separation process were approximately established. Further the separation conditions were optimized. [Results] The best technical parameters were as follows: feed refraction was 60% and column temperature was 65 ℃. At the same time quantity of flow in the entrance and eluent were 455 mL/h and 682 mL/h, respectively. The velocity of flow in the entrance and eluent were 37.4 mL/min and 29.6 mL/min, respectively. Besides, the circulating flow was kept within 364 mL/h. Finally, the outlet refraction of isomaltooligosaccharides was 20.40% with the purity of 90.20% and the yield of 85.50%. [Conclusion] The sequential simulated moving bed chromatographic separation equipment independently developed by the laboratory can efficiently purify isomaltooligosaccharides.