The invention relates to a seepage prevention method and a fixture for an aerial engine blade rabbet. The seepage prevention method for the aerial engine blade rabbet comprises the following steps of: after heating the cleaned blade rabbet, winding aluminum oxide cotton on the outer surface of the blade rabbet, and clamping the aluminum oxide cotton wound on the blade rabbet by two metal clamps; then putting the blade rabbet wrapped by the aluminum oxide cotton into a metal protective jacket together with the metal clamps; and taking mixtures of ferro-aluminum powders, aluminum-silicon powders and tetra-methylammonium chloride as seepage agents, and carrying out gas aluminizing in a conventional method. The aluminum oxide, used in the invention, can resist corrosive atmosphere, and can not generate any chemical reaction and further generate pollution to a blade. Due to the adoption of the seepage prevention method and the fixture for the aerial engine blade rabbet, seepage layers on the rabbet part can be completely removed by only carrying out processes of wet grit blasting and coloring for one time, the repeated processes of dry grit blasting and the coloring are avoided, the production efficiency is improved for 1-2 times, and 30-40% of cost is saved; and furthermore, the operation is simple, and the seepage prevention effect is good.