The invention discloses a method for preparing a bulk sintered Nd-Fe-B permanent magnet material. The method comprises the following steps of: preparing fine powder with the average particle size of 2.9 to 3.3 micrometers from raw materials which are prepared according to a required formula; adding the fine powder into a metal die cavity of a molding pressing machine; and arranging a molding magnetic field to ensure that the fine powder is prepared into a patch raw blank in a compression molding way under an electromagnetic induction oriented magnetic field. The method is characterized by comprising the following steps of: selecting at least two patch raw blanks; selecting the joint surfaces of the patch raw blanks on the premise of ensuring the consistent orientation of all patch raw blanks; clearing Nd-Fe-B attached powder on the joint surfaces of all the patch raw blanks; performing butt joint on all the patch raw blanks; putting the butt-jointed raw blanks into a die box made of rubber; performing vacuum encapsulation on the die box; keeping the pressure of an encapsulation body under the isostatic pressure of 180 to 220Mpa for 8 to 13 seconds; taking the butt-jointed raw blank combination body out; transferring into a sintering basin; and sintering in a vacuum furnace to form a compact bulk Nd-Fe-B blank body. The invention has the advantages that: the bulk sintered Nd-Fe-B permanent magnet material can be produced by the conventional universal equipment, and has high precision, stable magnetic performance and low preparation cost.