Abstract: Amino clay(hydroxyl magnesium silicate) powder with layered structure was prepared in alcohol solution taking MgCl₂ and silane coupling agent KH550 as the starting materials. The composition and microstructure of asprepared amino clay were analyzed by X-ray diffraction and Fourier transform infrared spectrometry. The tribological properties of as-prepared water-soluble amino clay as a water-based lubricant additive were evaluated with a four-ball friction and wear tester, and the morphology and elemental composition of the worn steel surfaces were analyzed by scanning electron microscopy and energy dispersive spectrometry. Results indicate that the amino-functionalized amino clay exhibited good dispersibility in water. In the meantime, as a water-based lubricant additive, as-prepared watersoluble amino clay was capable of forming a lubricating and repairing film composed of Mg, Si, O and Fe on worn steel surfaces, thereby effectively mitigating the wear of the steel-steel pair and inhibiting the corrosiveness of water to the steel frictional pair to some extent.