The invention discloses a preparation method of a Zn-Al-Ni anticorrosion functional impregnation layer, in which such elements as Al and Ni are added into a
zinc impregnation agent to change the organizational structure of the conventional
zinc and aluminum impregnation layer prepared through
mechanical energy aided impregnation. An impregnation agent is prepared according to the following ratio (based on a total number of 100 parts): 20-50 parts of
zinc powders (an impregnation supplying agent), 5-25 parts of aluminum powders (an impregnation supplying agent), 0.5-5 parts of
nickel powders (an impregnation supplying agent), 0.1-2 parts of
ammonia chloride (an activating agent), 0.1-2 parts of
rare earth (a catalyst), and of the balance of Al2O3 powders (a filler). The preparation method of the Zn-Al-Ni anticorrosion functional impregnation layer comprises the following steps: uniformly mixing the zinc powders, the aluminum powders, the
nickel powders, the
rare earth and the Al2O3 powders according to the ratio, and weighing the mixture for later use; and carrying out heat preservation for 3-5 hours under the following technical parameters: a heat preservation temperature of 450 DEG C, and an impregnation furnace rotation speed
ranging from 5r / min to 7r / min. The preparation method provided by the invention has the advantages that a high quality of the impregnation layer is ensured through adopted particle diameters of the powders in the impregnation layer formula, and the prepared Zn-Al-Ni impregnation layer achieves low thickness,
high surface compactness, high rigidity and excellent anticorrosion performance.