An　online　strategy-matching　method　for　transient　precaution　control　based　on　game　theory　is　proposed,　which　regards　the　contingencies　as　the　strategy　of　a　virtual　player　and　the　control　actions　as　that　of　a　dispatcher.　The　payoff　function　is　defined　as　the　product　of　variation　of　stability　margin　and　correction　factors　of　strategy　indicating　the　cost　of　control　action　and　the　influence　of　the　changing　environment　on　contingency,　respectively.　The　method　for　obtaining　Nash　equilibrium　is　given　by　transforming　the　gaming　model　into　a　dual　linear　programming　model,　while　the　strategy　with　maximum　expected　revenue　is　selected　as　the　precaution　action.　Finally,　the　method　is　verified　effective　on　a　New　England　test　system.　©　Right.