Oral cavity expander

The utility model relates to the technical field of oral care, in particular to an oral cavity expander which comprises a frame body, a lead screw is movably connected to the front side of the top of the frame body in a penetrating mode, the screwing directions of threads on the two sides of the surface of the lead screw are opposite, and movable plates are arranged at the top and the bottom of the surface of the lead screw in a threaded and sleeved mode. Supporting rods are riveted to the front side and the rear side of the left side of the movable plate, the surfaces of the supporting rods are movably sleeved with sleeves, expanding and supporting plates are riveted to the left sides of the sleeves, tongue pressing mechanisms are riveted to the tops of the expanding and supporting plates at the bottom, supports are riveted to the front side and the rear side of the frame body, and limiting frames are movably connected to the left sides of the supports in a penetrating mode; an inner cavity of the support is