The invention provides an automatic die-cutting machine and die-cutting method for double-sided PE coated paper cup production. The automatic die-cutting machine comprises a die-cutting mechanism, a conveying mechanism, a guide mechanism, a U-shaped support and a bottom plate, and solves the problems that when double-sided PE coated paper is conveyed and subjected to die-cutting, the movement track cannot be correctly guided, deflection is prone to occurring, and errors of the die-cutting size are caused; in addition, during die cutting, a blade directly falls to cut off, so that the double-sided PE coated paper moves, burrs of a notch are increased, the position of the notch is inclined, and the edge of the fan-shaped paper cup sheet is broken; paper cup pieces are connected with waste materials after die cutting forming, the waste materials need to be manually cleaned, and therefore production efficiency is reduced. The double-sided PE coated paper has buffer time during die cutting, and the double-sided PE coated paper is continuously conveyed, so that more die cutting wastes are generated, the utilization rate of die cutting forming of the double-sided PE coated paper is reduced, raw materials are wasted, the production cost is increased, and the like.