The invention relates to a method for producing ammonium metatungstate by a wolfram-containing waste and a device thereof. The method comprises the following steps: mixing the wolfram-containing wasteand an additive 1 to obtain a mixture; roasting the mixture, to obtain a roasted material; adding an additive 2 into the roasted material and reacting, to obtain a solid-liquid mixture; filtering thesolid-liquid mixture to obtain a filter residue and filtrate, adding the filter residue into ammonia water, performing extraction or ion exchange on an obtained ammonium tungstate solution, and evaporating and crystallizing an obtained ammonium metatungstate solution, to obtain the ammonium metatungstate. The method for producing the ammonium metatungstate by the wolfram-containing waste is suitable for recovering treatment of multiple wolfram-containing wastes, such as a floor material, a dust collecting material, a grinding material and a waste material generated in a hard alloy productionprocess, and a floor material, a dust collecting material and a waste material generated in production processes of wolfram carbide powder and tungsten powder; general material mixing devices and roasting devices are used, clotted slag is avoided, a tungsten recovery rate is high, and the method has great popularization significance.