Silicon　nanostructure-based　composites　have　recently　aroused　intensive　interest　because　of　their　promising　potential　to　convert　solar　energy　into　chemical　fuels.　Here,　we　report　a　facile　approach　to　construct　the　film　composites　of　n-type　CdS　quantum　dot　(QD)　decorated　p-type　vertically　aligned　one-dimensional　(1D)　silicon　nanowire　(SiNWs@CdS)　arrays　with　enhanced　activity　and　recyclable　operability　for　photocatalytic　hydrogen　evolution　in　comparison　with　the　single　component　counterpart.　The　photoelectrochemical　results　confirm　the　formation　of　a　p-n　heterojunction　in　the　interface　of　SiNWs　and　CdS　QDs,　which　can　create　an　internal　electric　field　to　facilitate　the　separation　and　transport　of　photoinduced　charge　carriers,　thereby　leading　to　the　concomitant　improvement　of　both　the　photoactivity　and　photostability　of　the　SiNWs@CdS　array　composite.　This　work　is　expected　to　provide　an　instructive　recipe　for　fabricating　p-n　heterojunction　1D-based　composite　arrays　with　a　film　structure　to　boost　charge　carrier　separation　and　transfer,　and　to　achieve　efficient　artificial　solar　energy　conversion.　©　2018　The　Royal　Society　of　Chemistry　and　the　Centre　National　de　la　Recherche　Scientifique.