Extraction of seal wort oligose with effect of reinforcing immune function from seal wort

The invention relates to a rhizome oligosaccharide which is extracted from rhizome and has the effect of enhancing immune function, the technical proposal is that a rhizome processed product is taken and smashed, ethanol with the weight concentration of 50 to 95 percent is added for carrying out ultrasonic or reflux extraction twice, the filtration is carried out, the filtrate is carried out the vacuum concentration till no alcohol smell exists, distilled water is used for fixing the volume which is equal to 1g/ml, a macroporous absorption resin is arranged on water solution for water washing, water washing liquid is collected and condensed to be in a thick paste state, thus obtaining a brown oligosaccharide extract, the yield is 9.0 percent to 13.6 percent, the extract mainly comprises fructose, glucose, sucrose, raffinose and other micromolecular sugars, the extract is dried to obtain powder rhizome oligosaccharide, the rhizome oligosaccharide can be effectively used for the preparation of drugs and health