Polycrystalline nickel-zinc ferrite ceramics were prepared within tens of seconds via ultrafast pulse electric current sintering without pressure. The phase composition and microstructure of the samples were characterized by X-ray diffraction and scanning electron microscopy, respectively. The static magnetic properties and Curie temperature of the samples were investigated by vibrating sample magnetometry. The main phase of the sintered sample was the same as that of the raw powder, and the maximum relative density of the sample reached 95.72%. The densification and grain growth of the sample were accelerated through the synergistic effect of the energy concentration of pulse current heating and Joule heating that was generated by the sample. The grains at the edge of the sample were larger than those at the center, which was attributed to the uneven temperature distribution in a sintering sample. The slight differences in specific saturation magnetization and Curie temperature of the samples were attributed to the slight difference in sample phase composition that was caused by partial nickel-zinc ferrite decomposition and Zn volatilization during sintering. The inferred critical grain size between the dual- and mono-domain was ~ 450 nm. The ultrafast pulse electric current sintering technique has the advantages of a heating energy concentration, high heating rate and energy saving. The technique provides an effective approach to prepare compact and ultrafine grain ceramics rapidly.