It is important to develop high emissivity infrared radiation materials for energy saving in high-temperature furnaces. In this work, Ni2+-doped MgCr2O4 materials were prepared by a high-temperature solid-phase reaction process. The effect of Ni2+ doping content on the infrared radiation properties of MgCr2O4 materials was investigated, and the mechanism of emissivity enhancement of MgCr2O4 materials was explored. The results show that Ni2+ ions can be doped into the lattice of MgCr2O4 materials, and the prepared Mg1-xNixCr2O4 (0.1≤x≤0.5) materials produce the lattice distortion and a small amount of Ni2+ valence state transformation. Also, the concentration of oxygen vacancies increases, the forbidden band width decreases with the increase of Ni2+ doping, thus improving the emissivity of the prepared materials in the near-mid-infrared band. The material with x of 0.5 (Mg0.5Ni0.5Cr2O4) has an average emissivity of 0.88 in the near infrared ref bands (i.e., 0.8-2.5 μm), which is 167% greater than that of the undoped specimens. Ni2+ ions doping enhances the lattice vibration absorption, free carrier absorption and impurity energy level absorption, and improves the infrared emissivity of MgCr2O4 materials in the near-mid-infrared band.