PtS/ZnIn2S4　nanocomposites　are　obtained　via　a　microwave-assisted　synthesis　followed　by　a　photoreduction.　The　resultant　PtS/ZnIn2S4　nanocomposites　are　used　as　an　effective　multifunctional　photocatalyst　for　the　reaction　between　alcohols　and　o-aminobenzamide　to　coproduce　quinazolinones　and　hydrogen　under　visible　light,　via　a　cascade　alcohols/aldehydes　transformation,　condensation　between　aldehydes　and　o-aminobenzamide,　as　well　as　the　dehydrogenation/cyclization　to　produce　quinazolinones.　PtS　acts　as　an　efficient　cocatalyst　to　promote　the　dehydrogenation　of　both　the　alcohols　and　the　condensation　intermediates　for　the　production　of　quinazolinones.　An　almost　complete　conversion　of　o-aminobenzamide　was　achieved　in　24　h,　with　a　yield　of　98.8%　to　2-phenyl-quinazline-4(3H)-one　and　quantitative　hydrogen　produced　over　PtS/ZnIn2S4　after　irradiated　for　24　h.　The　apparent　quantum　yield　at　450　nm　is　determined　to　15.2%.　The　superior　activity　observed　over　PtS/ZnIn2S4　nanocomposite　as　compared　with　that　over　either　NiS/ZnIn2S4　or　MoS2/ZnIn2S4　can　be　ascribed　to　a　moderate　binding　between　PtS　and　the　surface　adsorbed　H*.　This　study　supplies　an　effective,　green,　and　atom-economic　strategy　for　the　synthesis　of　quinazolinones　with　coproduction　of　hydrogen　under　visible　light.　This　work　also　demonstrates　the　high　potential　of　fabrication　of　metal　sulfide-based　multifunctional　catalysts　for　light-driven　one-pot　tandem/cascade　reactions.　©　2023　Wiley-VCH　GmbH.