The invention discloses a refining device and method for high-purity rare earth metal. The device comprises an electron beam generation device, a cavity, a box-type water cooling copper die, an insulation board, high-purity tantalum joints, an oxygen-free copper electrode base and a voltage-stabilized power source. The electron beam generation device is arranged above the cavity. A working platform for refinement is placed at the bottom of the cavity. The box-type water cooling copper die is placed on the working platform. The insulation board is laid on the inner side wall and the bottom of the box-type water cooling copper die. The rare earth metal is placed on the insulation board. The high-purity tantalum joints making tight contact with the left end and the right end of the rare earth metal are embedded in the insulation board. The oxygen-free copper electrode base is connected with a wire outside the cavity. The other end of the wire is connected with the voltage-stabilized power source. Electron beams released by the electron beam generation device punch the rare earth metal at the lower portion. The device is adopted in the method for refining rare earth. The device fully integrates the beneficial effects of three refining methods, so that smelting time is greatly shortened, and the purity of a target product is high.