Supramolecular gels hold great potential in engineering applications as lubricants. However, the pure organic network of the gel limits its rheological and lubrication performance. Here, we report a nanoporous material-functionalized supramolecular composite gel lubricant by incorporating polymer brush-grafted metal-organic framework (MOF) nanoparticles (NPs) as nanoadditives. The composite gel was produced by encapsulating poly(lauryl methacrylate) (PLMA) polymer brush-functionalized UiO-67 (UiO-67@PLMA) NPs in 500 SN base oil of a three-dimensional (3D) network formed by 12-hydroxystearic acid (12-HSA) through hydrogen bonding and van der Waals (vdW) interactions. The addition of UiO-67@PLMA NPs largely improved the thermal and rheological properties of the 12-HSA/500 SN gel, and the storage modulus and loss modulus increased significantly. Tribological tests showed that incorporating 0.40 wt% UiO-67@PLMA NPs into the composite gel reduced the coefficient of friction and wear volume by 45.68% and 86.85%, respectively. Furthermore, the UiO-67@PLMA gel demonstrated remarkable tribological performance under challenging conditions, such as 400 N, 65 Hz, and 160 °C. The outstanding lubrication performance of the supramolecular composite gel arises from the shear-triggered release of base oil and nanoadditives, which act as nanobearings and promote protective film formation.