The invention relates to the technical field of permanent magnet materials, in particular to a neodymium iron boron permanent magnet material and a preparation method thereof. The neodymium iron boronpermanent magnet material is prepared from, by mass, 21.85%-24.15% of neodymium, 0.91%-1.01% of boron, 7.5%-8.5% of praseodymium, 0.6%-0.8% of aluminum, 0.55%-0.65% of dysprosium, 0.15%-0.25% of gallium,0.13%-0.17% of copper, 0.11%-0.13% of zirconium, 1%-6% graphene and the balance iron. The preparation method of the material comprises the steps that raw materials except graphene, copper and aluminum are subject to smelting and ingot casting in advance and then are proportionally mixed with nano copper powder, nano aluminum powder and nano graphene sheets, the mixture is put in an oriented magnetic field for pressing and formation, and sintering is performed after isostatic pressing. The preparation method is simple in process, easy to control, the product performance is superior, the product quality is stable, and the prepared neodymium iron boron permanent magnet material is good in corrosivity, high in mechanical strength and good in machinability.