For the machine, the melting and casting are carried out in full vacuum and inert gas, the smelting process is automatically stirred, and the finally formed grain has uniform fineness and free oxidation. The heating coil is featured with low-voltage design, isolated heating, safe and stable properties. The material taking of granulation bucket is easy, the cooling water can be recharged, the whole granulation process is also carried out under vacuum, and the machine is particularly applicable to the easily oxidized metal and synthetic metal. The finished product is featured with free oxidation, uniform particles, good fineness, and excellent spherical property.