The invention discloses a production technology for a hard PVC high foaming plate. A fresh solvent barrel, a diaphragm pump, a fresh solvent storage groove, a charging tank, a kneader, a charge pump, a foaming machine, an automatic conveyor, a hot air circulation oven and a cutting machine, all of which are sequentially connected are included. A solvent recycling storage groove is further formed in front of the charging tank. A heating plate I, a die and a heating plate II are arranged in the foaming machine. The bottom of the heating plate I is connected with the top of the die, and the bottom of the die is connected with the top of the heating plate II. An inlet of the die is connected with an outlet of the charge pump, and an outlet of the die is connected with the kneader. Each of the heating plate I and the heating plate II is provided with a steam heating and circulation water cooling device. According to the production technology, the hardness and foaming ratio of the PVC foaming plate are greatly improved, and the problem that hard high foaming plate materials are unavailable for PVC in China at present is solved.