In　this　study,　the　visible-light-driven　[2　+　2]　photocycloaddition　of　1,4-dihydropyrazines　in　solution　was　reported.　The　N,N＇-diacyl-1,4-dihydropyrazines　with　different　substituents　showed　completely　different　reactivity　under　the　irradiation　of　a　430　nm　blue　light-emitting　diode　(LED)　lamp.　N,N＇-Diacetyl-1,4-dihydropyrazine　and　N,N＇-dipropionyl-1,4-dihydropyrazine　were　the　only　compounds　capable　of　undergoing　a　[2　+　2]　photocycloaddition　reaction,　yielding　syn-dimers　and　cage-dimers　(known　as　3,6,9,12-tetraazatetraasteranes)　with　overall　yields　of　76　and　83%,　correspondingly.　The　substituent-reactivity　effect　on　[2　+　2]　photocycloaddition　of　N,N＇-diacyl-1,4-dihydropyrazines　was　investigated　by　density　functional　theory　calculations.　The　results　show　that　the　substituents　have　little　influence　on　Gibbs　free　energy　for　the　[2　+　2]　photocycloaddition　and　mainly　affect　the　excited　energy,　reaction　sites,　and　the　triplet　excited-state　structures　of　1,4-dihydropyrazines,　which　are　closely　related　to　whether　the　reaction　occurs.　The　results　offer　insights　into　the　photochemical　reactivity　of　1,4-dihydropyrazines　and　an　approach　for　constructing　dimers　of　N,N＇-diacyl-1,4-dihydropyrazines　through　a　solution-based　visible-light-driven　[2　+　2]　photocycloaddition,　especially　for　the　construction　of　3,6,9,12-tetraazatetraasteranes.　Compared　with　the　solid-state　[2　+　2]　photocycloaddition　of　1,4-dihydropyrazine,　this　photocycloaddition　will　be　an　efficient　and　environmentally　friendly　method　for　synthesizing　tetraazatetraasteranes　with　the　advantages　of　milder　reaction　conditions,　simple　operation,　adjustable　reaction　amounts　by　omitting　the　cocrystal　growth　step,　etc.