Water-based　superlubricity　systems　have　unique　advantages,　such　as　low　friction　and　environmental　friendliness.　While　control　of　water-based　superlubricity　is　highly　attractive,　it　is　also　challenging.　The　superlubricity　transition　behavior　of　poly(vinylphosphonic　acid)　(PVPA)　lubricated　using　a　NaCl　solution　when　mixed　with　multiple　lubricants　was　investigated　in　this　study.　The　mechanisms　of　superlubricity　transition　were　investigated　by　exploring　the　internal　structural　changes　of　a　PVPA　coating　and　the　molecular　behaviors　at　the　PVPA　interface　affected　by　cations　through　X-ray　photoelectron　spectroscopy　(XPS)　depth　profiling,　quartz　crystal　microbalance　with　dissipation　(QCM-D),　and　molecular　dynamics　simulation.　The　type　and　magnitude　of　the　superlubricity　transition　caused　by　cations　with　different　valence　states　are　clearly　different.　The　introduced　monovalent　cation　that　can　stably　adsorb　on　the　PVPA　surface,　exhibits　a　strong　attraction　toward　the　surrounding　water　molecules,　instantaneously　strengthening　the　lubrication　at　the　PVPA　interface.　These　changes　at　the　interface　are　reversible　and　would　cause　a　sudden　decrease　in　the　coefficient　of　friction　(COF).　Adsorbing　an　introduced　divalent　cation　on　the　PVPA　molecular　chain　leads　to　the　transformation　of　the　PVPA　coating　from　a　stable　network　structure　to　an　unstable　bridging　structure.　The　sudden　increase　in　the　COF,　caused　by　the　altered　internal　structure　of　the　coating,　is　irreversible.　This　study　provides　theoretical　support　for　the　adaptive　control　of　water-based　superlubricity　and　intelligent　lubrication.　(c)　2022　Elsevier　B.V.　All　rights　reserved.