The invention relates to a powder with function of reducing blood sugar and blood fat and a preparation method thereof and belongs to the field of health products. The powder disclosed by the invention is prepared from inulin, cyclocarya paliurus leaves, yam, astragalus membranaceus, dendrobe and salviae miltiorrhizae. All the raw materials are selected from natural Chinese herbal medicines; no additive is added; the components are natural; the label is clean; the powder conforms to the idea trend for pursuing natural and healthy food of people; the dosage is less; the powder can be conveniently orally taken, can be directly dissolved in water for taking, can be dissolved in cold water and can be quickly absorbed. The preparation method for the powder provided by the invention is simple; the powder is suitable for large-scale production, is portable, has high stability and can be stored for a long time. An experiment proves that the powder provided by the invention has the function of reducing blood sugar and blood fat, has an obvious effect and can be used for preparing health food with function of reducing blood sugar and blood fat.