Method for improving coercive force of sintered neodymium-iron-boron magnet and application

The invention discloses a method for improving the coercive force of a sintered neodymium-iron-boron magnet and application, and the method mainly comprises the following steps: sequentially plating a metal aluminum film layer and a heavy rare earth metal film layer on the surface of the sintered neodymium-iron-boron magnet subjected to ultrasonic pickling from inside to outside through magnetron sputtering to obtain a semi-finished product, and then the semi-finished product is placed in an inert gas atmosphere to be subjected to high-temperature diffusion treatment and then cooled, and therefore the high-coercivity sintered neodymium-iron-boron magnet is prepared. On the premise of ensuring that the coercive force of the sintered neodymium-iron-boron magnet is improved, compared with a traditional magnetron sputtering diffusion method, the method has the advantages that the diffusion temperature can be reduced or the diffusion time can be shortened, so that the energy consumption is reduced, and the product