A　technique　for　dynamic　wetting　visualization,　based　on　the　critical　light　reflection,　is　developed.　The　technique　is　capable　of　real-time　charactering　the　shape　and　contact　angle　of　a　liquid　surface　curved　by　a　moving　rod.　A　particular　reflection　pattern　with　oval　or　diamond　shape　resulted　from　critical　reflection　of　the　curved　surface　is　observed.　Study　reveals　the　dependence　of　the　characteristic　width　of　the　pattern　on　the　critical　reflective　angle　decided　by　the　surface　shape.　The　correlations　of　the　width　to　advancing　or　receding　angle　are　also　experimentally　established.　The　rang　of　advancing　contact　angle　change　is　experimentally　found　over　50°　so　that　the　curved　water　surface　turns　from　upward　to　downward.　Theoretical　descriptions　based　on　dynamic　wetting　and　geometric　optics　are　used　to　analyze　the　formation,　the　change　and　the　optical　fringes　of　the　special　reflection　pattern,　and　which　account　for　most　of　the　observations.　©　2020　Elsevier　GmbH