The invention belongs to the field of preparation of graphene, and specifically provides a method for continuous preparation of graphene oxide nanoplatelets based on electrochemical treatment. According to the invention, continuous graphitization products like flexible graphite coiled materials, strip materials or carbon fiber wire materials are used as raw materials and stripped into the graphene oxide nanoplatelets successively through two treatment steps of electrochemical intercalation and electrolytic oxidation stripping under the driving of a feeding device, wherein the treatment step of electrochemical intercalation is as follows: with a graphite material as a positive electrode, introducing electricity into concentrated acid under the condition of soaking, allowing acid ions to enter into graphite layers under the driving of an electric field so as to form an intercalated continuous graphite material with first-level or low-level intercalation; and the treatment step of electrolytic oxidation stripping is as follows: with the intercalated continuous graphite material as the positive electrode, introducing electricity into an electrolyte aqueous solution, carrying out electrolytic stripping, and subjecting intercalated graphite to oxidation stripping by utilizing oxygen produced by electrolysis of water replaced into the graphite layers so as to obtain the graphene oxide. The method provided by the invention has the advantages of no metal impurities of a product, controllable degree of oxidation of graphene, continuousness and automation of a process, safety, low emission, etc.