The invention discloses an active carbon air filter element and a preparation method thereof. The active carbon air filter element comprises following raw materials, by weight, 12 to 14 portions of active carbon powder, 40 to 45 portions of microporous polyethylene powder, 1 to 2 portions of silver nitrate, 3 to 4 portions of sodium chloride, 2 to 3 portions of silane coupling agent KH550, 1 to 2 portions of zirconium tetrafluoride, 3 to 4 portions of graphite, 1 to 2 portions of silicon carbide, 4 to 6 portions of attapulgite, 2 to 3 portions of urea, 1 to 2 portions of azodicarbonamide, 12 to 14 portions of modified attapulgite, 3 to 4 portions of polyvinyl alcohol and an appropriate amount of water. Silver nitrate is taken as one of the raw materials of the active carbon air filter element, so that when the active carbon air filter element is used for filtration and adsorption, silver ions are capable of sterilizing, and realizing further purifying of air or water. Silicon carbide is taken as one of the raw materials, and is capable of improving wear resistance and strength of the active carbon air filter element. The active carbon air filter element is suitable to be used in severe environment; is high in purification efficiency, less in pressure loss, and long in service life; is resistant to high temperature and corrosion; and is capable of removing micro dust in the air.