The invention relates to a perforating device for thermoplastic plates, which relates to the technical field of a plate processing device. The device comprises an electromagnetic chuck, one side of the electromagnetic chuck is connected with the motion part, the other side of the electromagnetic chuck is connected with a mounting plate and a spike. When the electromagnetic chuck is powered on, the spike is attracted below the mounting plate by the electromagnetic force. A clamping part is arranged below the mounting plate, the thermoplastic plate is fixed by the clamping part, and a heating system is also provided to heat the thermoplastic plate. As the electromagnetic chuck is powered on or off, the spike can be attracted in or separated from the mounting plate, respectively. Therefore, the perforating device can make a new plate be pierced during the cooling and curing process of the perforated plate.