Method for extracting polysaccharides from radix millettiae speciosae

The invention discloses a method for extracting polysaccharides from radix millettiae speciosae. The method comprises the following steps: (1) the radix millettiae speciosae is dried for being crushedinto powder, and water is added for soaking the radix millettiae speciosae powder until to be softened; (2) the softened radix millettiae speciosae powder is poured into a high-pressure homogenizingmachine to be homogenized for a certain time under the condition of 6-15 MPa and then homogenized again under the condition of 20-30 MPa, homogeneous liquid is centrifuged under the condition of 3000-5000 r/min, and then supernatant is collected; (3) first microfiltration is carried out to the supernatant obtained in the step (2), an ultrafiltration membrane with molecular weigh cut-off of 5000 isselected for separation, and then filter liquor is collected; (4) ultrafiltration is carried out to the filter liquor obtained in the step (3), the ultrafiltration membrane with molecular weigh cut-off of 1000 is selected for