The invention discloses an impregnation method of aluminium electrolytic capacitor slugs, the impregnation time of which is short. The invention is characterized in that the method comprises the following steps: (1) placing the slugs to be impregnated in an impregnation vat in order; (2) vacuumizing the impregnation vat to be in the vacuum degree of 0.05MPa-minus 0.15MPa, keeping the pressure for 10min-15min, opening a connection valve, pumping an electrolyte solution to the impregnation vat and closing the connection valve; (3) vacuumizing the impregnation vat to be in the vacuum degree of 0.05MPa-minus 0.15MPa, and impregnating the slugs for 0.5h-20h; and (4) drying the impregnated slugs. The method of the invention has simpleness, practicability and convenient operation; through experiments, the impregnation time is greatly shortened, for example, the conventional impregnation time of the slug with a diameter of Phi16mm-Phi18mm is 15h-20h, and the impregnation time thereof is 10h-15h after the method is used, thereby greatly shortening technology time, improving production efficiency, and obviously improving product quality.