Crude polysaccharide diluted liquid contains plenty of suspended particles and colloidal impurities. Simple centrifugation only removes large solid contaminants and fails to eliminate micro colloids. This article shows laboratory test samples including polysaccharide diluted solution, feed liquid before centrifugation and centrifuged liquid. It analyzes the limitations of single centrifugation and introduces membrane separation technology for advanced purification. The low-temperature physical membrane process intercepts ultra-fine residual impurities while protecting polysaccharide active substances. Combined centrifugation and membrane filtration delivers stable, clear polysaccharide liquid for follow-up refining, which is an efficient purification solution for natural polysaccharide deep processing.