Based on the charge balance theory, in the course of modified epoxy resins with function-graphene, a new purification method has been proposed by adding a slight amount of electrolyte to destroy the charge balance of the function-graphene, thus accelerating the deposition rate of functionalized graphene oxide, and rapidly removing the excess BPA of the BPA functioned graphene (BPA-GO) under a low speed centrifugation. At the same time, a contrast experiment has been carried out with the traditional dialysis method adopted, and an analysis of the purification effect of the two methods has been made by using infrared spectroscopy and UV VIS spectrophotometer, followed by a tentative investigation into the effect of rotating speeds on the separation efficiency of the method by using centrifugal separation. The results show that the proposed method has no negative effects on the structure of the samples. Compared with the traditional method, the dialysis method exhibits its own advantages, with a high purification efficiency, low equipment requirements, and practical feasibility of industrial production.