The challenge of achieving effective lubrication and wear resistance at temperatures exceeding 600 °C is a significant hurdle for metallic materials. This is primarily due to their susceptibility to high-temperature softening and the rapid degradation of conventional lubricants. In this study, we propose a novel strategy to improve high-temperature lubrication and wear resistance by utilizing in-situ reaction-driven self-lubricating protection mechanisms within hierarchical high-entropy nanocomposites (HHENCs), which were fabricated via electron beam additive manufacturing (EBAM) using pre-alloyed (FeCoNi) 86Al 7Ti 7 powders. The HHENCs are characterized by a face-centered-cubic (FCC) matrix, and the multiscale hierarchical precipitates of the L1 2, body-centered-cubic (BCC) and L2 1 phases, which exhibit remarkable bifunctional heterogeneity. Firstly, the structural heterogeneity (multiscale precipitates) imparts significant strengthening and toughening effects, improving tribological performance. Additionally, the chemical heterogeneity (diverse affinities of metallic elements for oxygen) favors the formation of a unique multilayer oxide composite structure with self-lubricating properties. Through advanced tribological test and material characterization, we demonstrate that the formation of the multilayer oxide composite structure significantly reduces the coefficient of friction (CoF). At temperatures ranging from 600 to 900 °C, the CoFs reach as low as 0.16-0.29. The continuous plastic deformation of multilayer oxide composite structure during wear contributes to grain refinement, which promotes the formation of stacking faults (SFs) and deformation twins (DTs), enhancing the strength and wear resistance of materials. Our findings underscore the potential of multilayer oxide composite structure to achieve high wear-resistance at temperatures far exceeding those attainable by conventional lubricants, providing a promising pathway for the development of high-temperature self-lubricating alloys.