The invention provides a method for preparing a
polymer microporous foaming material by supercritical mould foaming. The method comprises the following steps of: heating a foaming mould on a mould press to the foaming temperature; placing a
polymer into the mould; closing the mould by using the mould press; sealing the mould; introducing
supercritical fluid, which swells and diffuses to the
polymer, into the mould; and opening the mould by using the mould press to release pressure and foam to obtain the polymer microporous foaming material. Compared with the prior art, the method has the advantages that: the high-temperature and high-pressure
supercritical fluid is used for swelling the polymer, so the moulding cycle is greatly shortened; the limit that only microporous foaming
sheet material with lesser thickness can be manufactured in the prior art is broken through, so a polymer microporous foaming plate with greater thickness can be manufactured; when the mould is opened, the pressure-releasing speed is high and the foaming pore core-forming speed is high, so the formed microporous foaming material has smaller foaming pores, higher pore density and more excellent performance; and multiple
layers of moulds can be placed on one mould press, so the method is suitable for industrialized scale production.