The density of cermet inert anodes in aluminum electrolysis is of great importance. Ni-NiFe2 O4 cermetswere studied with respect to their densification affected by ball milling time, particle size of raw powders, contentsof metallic phase, sintering atmosphere and temperature. The results show that, prolonging ball milling time willincrease the density with the optimum value of 150 min; cermets containing 0 - 15 %Ni(mass fraction) have high rel-ative density ranging from 94% to 96%, but with Ni content increasing, the density slightly decreases; weak reduc-tive atmosphere is favorable to densification; the relative density increases from 80.38% to 96.85% with the sinte-ring temperature increasing from 1 100 ℃ to 1 300 ℃ while it decreases at 1 400 ℃, which may be due to crystalgrain coarsening. So the sintering temperature of Ni-NiFe2 O4 cermets in current work should be controlled at 1 300℃, where the relative density is 96.85%.