The invention discloses a mechanical device, and in particular relates to a device for producing gluconic acid. The device comprises a clamping steel plate, a polar liquid flow channel plate, a platinum electrode, a bipolar membrane, an elastic partition plate, a hydroxyl difficult penetrating homogeneous phase cationic membrane, and the like, wherein the electrode adopts a titanium alloy or platinum electrode with higher efficiency; an elastic coating is coated on the elastic partition plate for sealing; a material liquid inlet, a material liquid outlet, a sodium hydroxide liquid outlet and a sodium hydroxide inlet are arranged on the clamping steel plate, which is beneficial to the safety in the transportation process; and a liquid guide hole is improved and adopts an elliptic liquid guide hole. The invention has the advantages of high yield, no pollution, low running cost, convenience for transportation, and the like and can be widely applied to a glucose producing enterprise.