A preparation method of a high-performance NdFeB rare-earth permanent-magnet material comprises the steps of (1) material preparation; (2) casting; (3) magnetic powder preparation; (4) magnetic field formation green blank preparation; (5) cold isostatic pressing; (6) low-pressure sintering, wherein a cold isostatic pressing green blank obtained in the step (5) is placed in a low-pressure sintering furnace, a temperature is started to be risen when vacuumizing is performed until pressure in the furnace is less than or equal to 1*10<-2>Pa, heat preservation is performed for 0.5-1.0 hour when the temperature is risen to 900-1,000 DEG C, vacuumizing operation is maintained during the temperature rising and heat preservation process, vacuumizing is stopped after heat preservation is ended, the temperature in the furnace is continuously maintained at 900-1,000 DEG C, high-purity inertia gas is introduced until the pressure in the furnace is 0.5-4MPa, and heat-preservation and pressure-preservation sintering is performed 5-30 minutes, heat preservation is stopped after sintering is ended, and a room-temperature high-purity inertia gas is introduced for cooling until a room temperature to obtain a sintered magnet; and (7) performing two-stage processing. By the method, the NdFeB rare-earth permanent-magnet material with favorable integral magnetic performance can be obtained, and the cost is reduced.