The present invention relates to the field of medical health care products, and disclosed are an Achyranthes bidentata Blume stem and/or leaf and/or root extract, an extraction method, and application. The extract is Achyranthes bidentata polysaeeharides, and monosaccharide basic structural units of the Achyranthes bidentata polysaeeharides comprise fructose and glucose. The Achyranthes bidentata polysaeeharides is prepared by purifying the Achyranthes bidentata Blume stem and/or leaf and/or root extract, and a molecular weight range of the Achyranthes bidentata polysaeeharides is 1-3 kD. In the extraction method for the Achyranthes bidentata Blume stem and/or leaf and/or root extract, an extraction agent is alkali water or ethanol. The method of the present invention overcomes the problems that there is a gap in research on Achyranthes bidentata Blume at present and the medicinal value is underdeveloped. Compared with published Achyranthes bidentata polysaeeharides, the Achyranthes bidentata polysaeeharides of the present invention has higher immunologic competence, hypoglycemic activity, and hepatoprotective activity, is conducive to promotion, and can be used for improving the development of immunologic competent, hypoglycemic, and hepatoprotective health care foods and drugs.La présente invention concerne le domaine des produits médicaux de soins de santé, et concerne un extrait de racine et/ou de feuille et/ou de tige d'Achyranthes Bidentata Blume, un procédé d'extraction et une application. L'extrait contient des polysaccharides d'Achyranthes Bidentata, et des unités structurales de base de monosaccharides des polysaccharides d'Achyranthes Bidentata comprennent le fructose et le glucose. Les polysaccharides d'Achyranthes Bidentata sont préparés par purification de l'extrait de racine et/ou de feuille et/ou de tige d'Achyranthes Bidentata Blume, et une plage de poids moléculaire des polysaccharides d'Achyranthes Bidentata est de 1-3 kD. Dans le procédé d'extrac