Abstract: The reaction-sintering thermodynamic conditions in the synthesizing process of NiFe2O4 with NiO and Fe2O3 as main raw materials were investigated, and the bending strength and high-temperature conductivity of the synthesized spinel inert anode samples sintered secondarily on different conditions were measured. The results showed that the thermodynamic conditions are available to the solid-phase reaction of NiO with Fe2O3, and the solid-phase reaction goes on with the densification process though the former ends up earlier than the later. If an inert anode is synthesized from powdered material at 900°C without precompaction for 6 hours, then crushed up and pressed and sintered secondarily, the bending strength and high-temperature conductivity of the sample are maximum with best sintered performance provided. It was found that the crushing process is also very important to improve the activity of powdered material, as well as improving the sample's conductivity and mechanic properties.