A clamping device for a wrapping die contains symmetrically arranged overpressure resistant air bags filled with magnetic powders and two magnetic field generation devices for providing the magnetic powders with magnetic fields. Under the action of the magnetic fields, two mutually close ends of the two magnetic powders generate opposite magnetic poles. According to the invention, the magnetic powders are filled into the air bags, and magnetic force of the magnetic powders is utilized to clamp glass. Due to the characteristics of the air bags filled with the magnetic powders, the clamping device can be suitable for effective positioning of glass of different shapes and geometrical dimensions and provides enough clamping force so as to guarantee reliable positioning and clamping of glass. Therefore, the quality of produced finished products can be greatly improved, and the production cost can be saved.