Ferrite is frequently employed as a high-efficiency microwave absorption material (MAM). Herein, a novel and prospective high-temperature mechanochemical (HTMC) method was employed to fabricate pure-phase spinel zinc ferrite powders with a spherical structure. After that, the chemical compositions and structures, microscopic morphology, static magnetic characteristics, and microwave absorption properties of the powders were examined. The powder achieves a minimum reflection loss of -54.7 dB at a matching thickness of 4.4 mm, at which time the effective absorption bandwidth approaches 3.9 GHz. The superior microwave absorption ability of the powders is attributable to the favorable cooperative impact between dielectric and magnetic losses. Therefore, the as-prepared zinc ferrite powders can be utilized as high-efficiency MAM. The HTMC method has considerable potential for the large-scale preparation of high-performance MAM.