The invention discloses a kind of fine powders for preparing polymannan extract, comprising steps of the Alose of the freeze-drying of specified amount is weighed, wherein measuring the moisture content of correction The Alose of dissolution freeze-drying forms solution in deionized water First volume organic solvent is added into solution, to form the first mixture Wherein the organic solvent and the ratio between deionization cooling water and capacity are at least 2.5:1 Allow the first stabilized with mixture at least 8 The extraction volume that quantitatively the second organic solvent is added in supernatant from the first mixture and quantitative supernatant are to form the second mixture It is centrifugated second mixture The presence of observation is deposited in the second mixture It is added in the volume and the first mixture of third organic solvent and precipitates, if any, observe in the second mixture The first mixture of supernatant is decanted by siphon, wherein decantation, which has been carried out only to work as to be not observed, is deposited in the second mixture Precipitating is filtered from vacuum under the first mixture filter paper and suction funnel The powder polymannan extract of recycling and pass through scraping from suction funnel In the polymannan extract freeze-drying bottle that powder is put into, in capping refrigerator at least 8 The polymannan extract lyophilised bacteria of lyophilised bacteria freeze-dried powder The grinder of lyophilised powder polymannan extract is ground to texture.
