The utility model relates to an automatic raw-cadmium feeding device, which comprises a raw-cadmium platform lift cylinder, a raw-cadmium platform, a positioning pin, a raw-cadmium joint, a steel wire rope, a fixed pulley, a guide bar, a movable pulley, a slide block, a slide-block lift cylinder and a bracket, wherein two bearings are arranged at the bottom of the raw-cadmium platform and respectively connected with and supported by a raw-cadmium melting pot and the raw-cadmium platform lift cylinder; a through hole is formed at one end of a raw-cadmium ingot, and one end of the raw-cadmium joint is inserted into the through hole; a small hole is formed at the other end of the raw-cadmium joint to allow one end of the steel wire rope to conveniently penetrate the small hole to be fixedly connected with the raw-cadmium joint; the other end of the steel wire rope is fixed on a bracket and linked with the small hole of the raw-cadmium joint through the fixed pulley and the movable pulley; and the slide-block lift cylinder is arranged below the slide block and connected with the slide block through the bearings. The automatic raw-cadmium feeding device achieves automatic quantitative feeding, realizes stability of liquid level in the melting pot, and simultaneously reduces the labor intensity.