OBJECTIVE： To optimize the separation and purification technology of ginseng acidic polysaccharides， with the spray powder made of the residue after ethanol extraction from Panax ginseng as the raw material. METHODS： Taking the content of ginseng acidic polysaccharides， which was calculated with D-galacturonic acid as the reference substance， as the index， the method and condition in the preparation technology including resin separation and purification， desalination and drying were optimized， and the lab-scale test and pilot-scale test were conducted for verification. RESULTS： The D900 anion resin was used to purify and separate ginseng acidic polysaccharides， where elution was made successively with water and 0.3 mol/L NaCl solution at a flow rate of 2 BV/h， with a sample amount of 7.2 mg/g （crude polysaccharide/dry resin）， a diameter to height ratio of 1 ∶ 7 and an elution volume of 5 BV. The ultrafiltration method was used for desalination， where molecular weight cut-off was 1 kD. Spray drying was chosen for the preparation of ginseng acidic polysaccharides powder， the purity of which was 94.7％ in the lab-scale test. In the pilot-scale test， the RSDs of all indexes were lower than or equal to 2.42％ （n＝3）. CONCLUSIONS： The optimized separation and purification technology of ginseng acidic polysaccharides is stable， reliable， simple， easy， and it is suitable for industrialized production of high-purity products.