In liquid lubrication, the stability of the lubricating film and friction coefficient is governed by the liquid type and contact conditions. However, altering the friction coefficient of the liquid on some specific surface under constant conditions (such as speed, pressure. etc) is challenging. In this work, we developed a non-contact and reversibly switchable approach to control the nano friction of phosphonium-based ionic liquid (ILs) [P 4,4,4,8][BOB] on titanium oxide (TiO 2) surfaces via ultraviolet light. The co-ion effect promotes anion adsorption, generating an ordered interfacial structure and a novel sliding interface that favors the formation of elastic hydrodynamic or mixed lubrication regimes, thereby reducing friction by over 60 % compared to the initial dark-state condition and achieving superlubricity (friction coefficient μ < 0.01) under high contact pressure (24 MPa) on sub-nanometer rough TiO 2 surfaces. The study demonstrates under photo-induced activation, TiO 2 reacts with adsorbed water molecules to form a hydroxyl network and undergo protonation reactions, resulting in a positive surface charge. Combined simulation and force curve measurements, it is revealed that this condition will lead to an orderly and stable arrangement of ILs within near-surface layers. These findings offer valuable insights for the design of light-responsive lubricants and their integration into MEMS/NEMS.