Neodymium-iron-boron magnet and preparation method thereof

The invention provides a neodymium iron boron magnet and a preparation method thereof. The preparation method of the neodymium-iron-boron magnet comprises the following steps: S1, providing a neodymium-iron-boron substrate; s2, mixing the rare earth hydride alloy powder, a binder A, an organic solvent B and an additive C to obtain a coating; s3, the surface of a neodymium iron boron matrix is coated with the coating, and a neodymium iron boron magnet is obtained through grain boundary diffusion treatment; wherein the binder A is selected from one or more of polyether sulfone resin, ethylene-vinyl acetate copolymer, polyethylene, thermoplastic polyurethane, polyvinyl alcohol, polyvinyl butyral ester, polyamide, polyvinylidene fluoride, phenolic resin, alkyd resin, acrylic resin, epoxy resin, oleamide, methyl cellulose and hydroxymethyl cellulose. The additive C comprises metal inorganic salt and/or metal inorganic salt oxide. According to the technical scheme, the neodymium-iron-boron magnet is good in magneti