A magnetic ionic liquid (abridged as MIL) [C₆mim]₅[Dy(SCN)₈] was prepared and used as the magnetic lubricant of a steel-steel sliding pair. The tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant (abridged as MF; the mixture of dioctyl sebacate and Fe₃O₄, denoted as DIOS-Fe₃O₄) as a control. The lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS, XPS, and profilometry, as well as measurement of the electric contact resistance of the rubbed steel surfaces. The results revealed that the MIL exhibits better friction-reducing and antiwear performances than the as-received MF under varying test temperatures and loads. This is because the MIL participates in tribochemical reactions during the sliding process, and forms a boundary lubrication film composed of Dy₂O₃, FeS, FeSO₄, nitrogen-containing organics, and thioether on the rubbed disk surface, thereby reducing the friction and wear of the frictional pair. However, the MF is unable to form a lubricating film on the surface of the rubbed steel at 25 ^°C, though it can form a boundary film consisting of Fe₃O₄ and a small amount of organics under high temperature. Furthermore, the excessive Fe₃O₄ particulates that accumulate in the sliding zone may lead to enhanced abrasive wear of the sliding pair.