The invention discloses a method for recycling cadmium from metallurgical cadmium-contained dust and a device for recycling cadmium from a cadmium-ammonia solution. The metallurgical cadmium-containeddust is subject to ammoniacal circular leaching, when the lead/cadmium molar ratio in the solution is smaller than 0.01, the circular leaching process is ended; after leaching is finished, liquid solution separation is carried out, and the cadmium-ammonia solution is obtained; the proper amount of vulcanizing agent is added to enable impurity ions in the cadmium-ammonia solution to be subject tovulcanization precipitation separation. After impurity removal, liquid is placed in an ultrasonic enhancing electric strengthening replacement cadmium extraction key device to be subject to efficientcadmium extraction, and high-grade sponge cadmium and zinc-ammonia solution can be obtained. The sponge cadmium can be directly used for briquetting distillation or fusion casting-electrolytic refining to obtain high-purity cadmium. The zinc- ammonia solution can be directly turned into an electric zinc system to produce electric zinc.