The invention provides a modification method for complex special-shaped WC-Co hard alloy. The modification method comprises the steps that materials are mixed, then subjected to wet grinding, drying, plasticizer blending, pressing forming and presintering and machined to be of a required shape, pressure sintering is conducted, and the alloy is obtained. The presintering temperature is 850-950 DEG C. The product obtained after pressing forming is presintered at the temperature of 850-950 DEG C so as to have certain bonding capacity and is not completely alloyed; then, the product is machined to be of a required hard alloy product shape; and finally, pressure sintering is conducted, and the hard alloy is obtained. Through the modification method, the problem that complex products of hard alloy are difficult to form can be solved, produced products do not need subsequent machining any more, meanwhile, the problem that hard alloy is prone to being deformed in the production process is solved, and the subsequent machining cost is reduced.