The invention discloses a powder forging and molding method for preparing a porous amorphous alloy block material. The method comprises the following steps of: after respectively sieving amorphous powder and a powdered NaCl pore-forming agent, proportionally weighing the two components according to a porosity requirement; after uniformly mixing the components by a material mixer, carrying out sheathing, degassing and enveloping; carrying out heating and heat preservation on the sheathed and enveloped powder in a cold liquid phase area (Tg-Tx) for 5-15 minutes; forging and molding according toa set forging ratio, maintaining pressure for 30-90s and then forging; removing sheaths by adopting a machining method; and removing the pore forming agent by a water dissolving method to obtain the porous amorphous alloy block material. The method is simple and easy to apply, the prepared porous amorphous alloy material has the characteristics of controlled porosity, opening structure, uniform pore size distribution, and the like; meanwhile, the structural behavior of the powder can also be maintained. The dissolution of the pore forming agent is environmentally friendly, and the pore forming agent can be repeatedly used after treated.