Method for purifying and preparing stevioside and rebaudioside-A

The invention relates to a method for simultaneously preparing high-purity stevioside and rebaudioside-A in the technical field of biological medicines. The method comprises the steps of absorbing a stevia rebaudiana ethanol extracting solution by using macroporous resin, and eluting the stevia rebaudiana ethanol extracting solution to obtain a stevioside and rebaudioside-A extract; then, carrying out a silica gel column chromatography on the extract, eluting the extract, and then, collecting distillation fractions in the extract; finally, recrystallizing by using methanol to obtain a stevioside and rebaudioside-A refined product with the purity of over 98%. The method has the advantages of high purity, high yield, simple process, low cost and the like.