Photocatalytic　organosilicon　transformation　is　a　green　and　emerging　synthetic　strategy　toward　silyl　ethers　production.　This　approach　takes　advantage　of　the　highly　reactive　photogenerated　electron-hole　pairs　to　trigger　redox　reactions　for　chemical　transformations　under　mild　conditions.　However,　the　development　of　heterogenous　photocatalysts　for　silyl　ethers　synthesis　is　greatly　hampered　by　the　lack　of　sufficient　reactive　sites　on　the　catalyst　surface　for　the　adsorption　and　activation　of　silanes.　Herein,　we　demonstrate　that　the　light-induced　sulfur　vacancies　(SVs)　in-situ　generated　on　ultrathin　CdS　nanosheet　(CdS-NS)　can　function　as　typical　Lewis　acid　sites　to　adsorb　and　activate　silanes　via　the　formation　of　Si-H　center　dot　center　dot　center　dot　Cd　coordination　species.　In　addition,　these　electrondeficient　SVs　can　also　trap　the　photogenerated　electrons　to　promote　charge　separation.　The　CdS-NS　with　SVs　exhibits　an　excellent　photocatalytic　performance　toward　silyl　ethers　synthesis　while　producing　H2　simultaneously.　This　synthetic　strategy　based　on　in-situ　creation　of　abundant　Lewis　acid　sites　on　photocatalyst　surface　to　activate　silanes　will　have　broad　implications　in　the　development　of　high-performance　photocatalysts　for　organosilicon　transformations.