The　practical　application　of　lead-free　double　perovskite　Cs2AgBiBr6　in　photocatalytic　H-2　evolution　is　still　restricted　due　to　the　low　activity　and　poor　stability.　The　rational　design　of　lead-free　halide　double　perovskites　heterojunctions　with　efficient　charge　transfer　and　effective　active　sites　is　a　potential　route　to　achieve　the　ideal　prospect.　Herein,　in　this　work　an　S-scheme　heterojunction　of　Cs2AgBiBr6　with　enriched　Br-vacancies　and　WO3　nanorods　(V-Br-Cs2AgBiBr6/WO3)　obtaining　excellent　visible-light　responsive　photocatalytic　H-2　evolution　performance　and　durable　stability　is　reported.　The　S-scheme　heterojunction　driven　by　the　unaligned　Fermi　levels　of　these　two　semiconductors　ensures　the　efficient　charge　transfer　at　the　interface,　and　density　functional　theory　calculations　reveal　the　enriched　Br　vacancies　on　Cs2AgBiBr6　(022)　surfaces　introduced　by　atom　thermal　vibration　provide　effective　active　sites　for　hydrogen　evolution.　The　optimized　V-Br-Cs2AgBiBr6/WO3　S-scheme　photocatalyst　exhibits　the　photocatalytic　hydrogen　evolution　rate　of　364.89　mu　mol　g(-1)　h(-1)　which　is　4.9-fold　of　bare　V-Br-Cs2AgBiBr6　(74.44　mu　mol　g(-1)　h(-1))　and　presents　long-term　stability　of　12　h　continuous　photocatalytic　reaction.　This　work　provides　deep　insights　into　the　photocatalytic　mechanism　of　V-Br-Cs2AgBiBr6/WO3　S-scheme　heterojunctions,　which　emerges　a　new　strategy　in　the　applications　of　perovskite-based　photocatalysts.