Abstract: HDDR (hydrogenation-disproportionation-desorption-recombination) process is an effective means by which the anisotropic Nd2Fe14B-base magnetic powder can be prepared. vacuum HDDR process, i.e. the alloy is heated to the temperature about 820°C in vacuum and then HD reactions occur under the certain hydrogen press are with the addition of the alloying element Ga affects the magnetic properties of Nd13Fe64.4-yCo16 B6.5Zr0.1Gay (y=0.1, 0.3, 0.5, 1.0) alloy was studied. The results indicated that in the vacuum HDDR process, the HD steps are the key to spur the alloy on to anisotropy, and applying the low-vacuum high-temperature schedule to the desorption step will make sure that the alloy is anisotropic. The alloying element Ga contributes to refining the grains of main phase and improving the comprehensive magnetic properties of the alloy, of which the best atom fraction is 0.5%. Treated by the vacuum HDDR process, the Nd13Fe63.9Co16 B6.5Zr0.1Ga0.5 alloy provides its best magnetic properties, i.e. iHc=1018 kA·m^-1, Br=1.32 T, (BH)max=118.6 kJ·m^-3 and DOA=0.787.