Abstract: Attapulgite is a water-containing magnesium-aluminum-rich silicate clay mineral with one-dimensional rod-like morphology, the structural layer is composed of two layers of silica-oxygen tetrahedra and one layer of magnesium-oxygen octahedra. The unique layer-chain microporous structure enable sit to utilize the mechanical energy released from the friction process to generate physicochemical interactions in the lubricant medium to form a layer of oxide-based metal-ceramic self-healing film with high hardness, high strength and smoothness. It can achieve the healing effect on the worn surface and thus improve the tribological properties of the metal-based materials. It has been reported that as an additive in lubricant oils or greases, attapulgite fibers have been shown to be effective in reducing the friction and wear of steel contacts. As a result, layered silicate minerals are attracting more attention for their excellent tribological properties, simple processing, low cost and environmental friendliness in industry. They are expected to be an alternative to conventional antiwear additives containing contaminant elements such as S, P and Cl, and can be used in engines, transmissions, large industrial equipment and other lubrication systems to achieve energy savings and maintain reliability. Previous studies on attapulgite have mainly focused on its effect on its tribological properties, however, the research on its anti-wear and the self-repairing mechanism on the worn surface, especially its micro-mechanism for anti-wear repair of metal friction substitutes, has not been sufficiently investigated. In this study, the effects of incorporating glycerol monooleate-modified attapulgite into PAO6 base oil on the friction and wear characteristics of GCr15 steel tribopairs were thoroughly investigated. Employing an SRV high-frequency reciprocating tribometer, a comprehensive analysis was conducted. Various analytical techniques, including scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, confocal spectroscopy and X-ray photoelectron spectroscopy were utilized to determine the surface morphology, elemental composition, and structural features of the wear scar. The results disclosed the mechanism by which attapulgite additives assist in the repair of wear scars and enhance tribological properties. It was found that the addition of glycerol monooleate-modified attapulgite significantly improved the tribological performance of GCr15 steel, evidenced by a 57.1% reduction in the friction coefficient and an 86.3% decrease in wear rate. This enhancement was attributed to the anti-friction properties of glycerol monooleate. Furthermore, attapulgite was observed to form a sturdy, wear-resistant repair film on the wear scar surface, significantly increasing wear resistance. Under high-load conditions, attapulgite undergone tribochemical reactions, resulting in the formation of a composite repair film. This film comprising an iron oxide layer atop the substrate, with additional layers of silicate components, a hard ceramic phase and a trace amount of carbon preferentially deposited in the furrows of the wear scar and gradually extended over the entire contact interface. The outcomes of this research highlighted the role of glycerol monooleate-modified attapulgite, holded crucial implications for the development of advanced lubricants and offered a strategic pathway to significantly enhance the longevity and performance of mechanical systems.