Although　continuous　flow　synthesis　using　microtubing　reactors　has　provided　a　wealth　of　opportunities　for　homogeneous　photochemical　synthesis　and　has　proven　particularly　beneficial　in　scaling　up　processes,　employing　continuous　flow　technology　to　scale　up　heterogeneous　photoreactions　is　challenging　due　to　the　issues　including　handling　of　solids,　poor　light　penetration,　and　commonly　lengthy　reaction　time.　Here　we　present　a　solution　to　these　issues　by　changing　the　continuous　flow　mode　to　a　high-speed　circulation　flow　mode.　The　high　flow　rate　set　in　a　circulation　flow　reactor　overcomes　solid　sedimentation　to　prevent　clogging　and　improve　the　mixing　efficiency.　We　successfully　conducted　100　g-scale　C-N　and　C-S　cross-couplings　using　a　heterogeneous　photocatalyst　and　a　nickel　catalyst　in　the　flow　reactor　that　significantly　outperformed　conventional　batch　reactors.　The　photocatalyst　was　recycled　and　reused　10　times　to　achieve　a　kilogram-scale　synthesis　without　obvious　deactivation.　Semicontinuous　production　was　achieved　via　automated　feeding　and　collection,　and　a　photopromoted　gas/liquid/solid　three-phase　trifluoromethylation　reaction　was　employed.　A　kilogram-scale　amount　of　starting　material　was　successfully　transformed,　resulting　in　a　43.2%　yield　of　trifluridine.　Our　study　suggests　that　a　circulation　flow　reactor　with　high　flow　speed　will　become　a　crucial　tool　in　the　synthetic　chemist’s　toolbox　because　of　its　simple　infrastructure,　ease　of　operation　and　automation,　significant　efficiency　improvement　compared　to　conventional　batch　reactors,　scalability,　improved　safety,　and　tolerance　of　solids.　©　2024　American　Chemical　Society.