The invention discloses a method for eliminating the decarburization defect of a hard alloy, and belongs to the field of hard alloy manufacturing and production. The method comprises the following steps that 1, titanium dioxide, carbon black and a solvent are prepared into a coating; 2, the coating is uniformly applied on the surface of the hard alloy, and decarburization resintering is carried out; and 3, sand blasting is carried out on the hard alloy after decarburization resintering is carried out. According to the method, the coating covers the decarburizated parts and does not cover the qualified parts, and therefore the decarburizated parts can be selectively sintered again; the product can be directly placed on an original graphite boat for bearing the product after the coating is applied on the surface of the product, so that a special boat is not needed; and resintering is carried out through a vacuum sintering furnace or a low-pressure sintering furnace, no pollution is caused to the sintering furnace and the pipelines of the sintering furnace in the sintering process of the pasty coating under the vacuumizing condition, and therefore any cleaning or a special sintering furnace is not needed. The method for eliminating the decarburization defect of the hard alloy is capable of realizing the elimination of the decarburization defect of the hard alloy, short in workingprocedure, and low in production cost.