Ultraviolet　(UV)　photodetectors　(PDs),　which　can　convert　ultraviolet　light　into　electrical　signals　for　dynamic　monitoring,　have　attracted　tremendous　attention　to　protect　humans　from　diseases　induced　by　harmful　light　radiations.　However,　there　are　numerous　challenges,　such　as　unsatisfied　transparency,　poor　mechanical　flexibility　and　low　photoelectric　efficiency,　in　the　development　of　superior　PDs,　which　has　hindered　the　further　development　of　PDs.　In　this　study,　a　full　transparent　vertical　phototransistor　by　sandwiching　indium　tin　oxide　(ITO)　between　a　single-walled　carbon　nanotube　(SWCNT)　source　and　drain　electrode　is　invented　for　high-performance　transparent　UV　photodetectors.　Moreover,　benefited　from　the　nano-scale　transmission　channels　in　the　vertical　direction　and　rational　selection　of　materials,　the　photodetector　exhibits　superior　photoelectric　performance,　particularly　in　extremely　high　photoresponsivity　of　up　to　1.02　x　10(4)　A　W-1　and　photosensitivity　above　4.2　x　10(5)%.　Our　transparent　photodetector　is　competitive　and　superior　to　other　reported　planar　TFTs　or　two-terminals　devices.　Moreover,　the　photodetectors　maintain　transparency　of　over　85%　and　high　detectivity　of　up　to　1.73　x　10(16)　Jones　under　a　15　mm　bending,　which　ensures　outstanding　mechanical　robustness　against　mechanical　bending.　This　study　establishes　a　new　approach　for　high-performance　transparent　flexible　UV　photodetectors　and　shows　great　potential　for　next-generation　＂see-through＂　electronic　devices.