The invention discloses a processing method for improving strength and toughness and dimensional stability of whisker reinforced aluminum-based composite material forged blanks, and belongs to the field of whisker reinforced aluminum-based composite material processing. The processing method comprises the following steps: step one, a cast ingot is preheated while an upper anvil and a lower anvil of a press machine are preheated; step two, the cast ingot is placed on the press machine, the cast ingot is subjected to axial upsetting, and then the cast ingot is subjected to radial upsetting, andthen radial upsetting is carried out after 90 degrees are rotated in the circumferential direction; step three, the operations of the step two are repeated; step four, a forged blank is placed in warmwater for quenching; step five, aging treatment and air cooling to room temperature are carried out; step six, the forged blank is Immersed in cooling liquid for treatment, step seven, the forged blank is taken out and rapidly put into liquid nitrogen for treatment, step eight, the forged blank is taken out and rapidly dipped in the cooling liquid for heat preservation; step nine, the forged blank is taken out, and after the forged blank heated to room temperature, the forged blank is heated for heat preservation, and air cooling to room temperature is carried out; step ten, the operations from step six to step nine are repeated. According to the processing method for improving the yield strength, the tensile strength and the micro-yield strength of the whisker reinforced aluminum-based composite material forged blanks, the strength and toughness and dimensional stability of the whisker reinforced aluminum-based composite material are remarkably improved.