Grain boundary diffusion neodymium iron boron magnet base material, grain boundary diffusion neodymium iron boron magnet and preparation method of grain boundary diffusion neodymium iron boron magnet

The invention provides a grain boundary diffusion neodymium-iron-boron magnet base material, a grain boundary diffusion neodymium-iron-boron magnet and a preparation method of the grain boundary diffusion neodymium-iron-boron magnet base material. The grain boundary diffusion neodymium-iron-boron magnet base material comprises the following components in percentage by mass: more than 29% and less than 30% of Re and 0.97% of 1t, blt; the alloy comprises the following components in percentage by weight: 1% of rare earth elements, less than or equal to 0.4% of Cu + Ga, less than or equal to 0.2% of Ti + Zr, less than or equal to 10% of Co and the balance of iron and inevitable impurities, and Re comprises any one or more of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium. By controlling the ratio of the elements, the grain boundary diffusion efficiency and diffusion depth can be improv