Preparation method of dihydroquercetin

The invention discloses a preparation method of dihydroquercetin, and belongs to the field of medicine synthesis. The method comprises the following steps: adjusting a reaction solvent water to be alkaline by using an alkalization reagent to obtain an alkaline aqueous solution; dissolving quercetin dihydrate in an alkaline aqueous solution, and adding an oxygen-containing sulfite binary combined reducing agent for reduction reaction to obtain an end-point reduction reaction solution; diluting the end-point reduction reaction liquid with water, acidifying, aging and filtering to obtain filtrate and a filter cake; performing extraction, washing, drying and vacuum concentration on the filtrate to obtain a concentrated crude product; and recrystallizing the concentrated crude product to obtain the dihydroquercetin. The preparation method has the advantages of easily available raw materials, simple process and low production cost, and is especially suitable for industrial production. 本申请公开了一种二氢槲皮素的制备方法，属于药物合成领域。所述