Fe3O4/ZrO2 composites were prepared by high-energy ball milling. The principle of coating of magnetic composite particles was deeply investigated. The bonding strength of Fe3O4/ZrO2 magnetic composite particles can be predicted by combining deduced maximum overlap amount of the ZrO2 nanoparticle and Fe3O4 particle and surface energy of particles. Morphologies, magnetic properties and element compositions of samples were analyzed using TEM, VSM, EDS measurement. In addition, the properties of samples were explored qualitatively and quantitatively. According to the results, as rotational speed increases, specific saturation magnetization and coercivity of samples decrease. When the rotational speed of the ball mill is 120r/min, both coefficient of thermal expansion and residual radial compressive stress of samples are the minimums. ZrO2 nanoparticles have the best uniform distribution on the surface of Fe3O4 particle. Fe3O4/ZrO2 magnetic composite particles have the strongest bonding and the best coating. The friction coefficient of the composites is the most stable, and Fe3O4/ZrO2 composites have also good mechanical properties. Briefly, the prepared Fe3O4/ZrO2 composites have good comprehensive properties at 120r/min.