The present invention relates to a double membrane-structured mouthpiece for oral cleaning and an oral cleaning device using the same, having a double membrane structure and differentiating diameters of communication holes and connection holes in order to distribute a force applied to the inside of the oral cavity and to clean teeth and all range within the oral cavity regularly. The mouthpiece comprises: a base member having the shape of a horseshoe recessed inward so as to surround a set of teeth, and a plurality of communication holes formed such that a cleaning liquid passes toward the set of teeth； and a cover member surrounding the outer surface of the base member, and having a plurality of connecting holes being formed such that the cleaning liquid flows in/out, wherein the base member and the cover member are partially bonded such that a space is formed between double membranes configured by the base member and the cover member. In addition, a device for cleaning an oral cavity using a double membrane-structured mouthpiece for cleaning the oral cavity according to the present invention comprises: a double membrane-structured mouthpiece for oral cleaning； a supply line for connecting the double membrane-structured mouthpiece for cleaning the oral cavity to a cleaning liquid tank； a discharge line for connecting the double membrane-structured mouthpiece for cleaning the oral cavity to the cleaning liquid tank； a suction pump for providing the discharge line with a suction force such that the double membrane-structured mouthpiece for cleaning the oral cavity is forced against a gum to form vacuum pressure, and supplying the cleaning liquid to the double membrane-structured mouthpiece for cleaning the oral cavity through the supply line by means of the vacuum pressure to discharge the cleaning liquid through the discharge line； and channel switching means provided in the supply line and in the discharge line, so as to switch the direction of flow of the cleaning
