Photocatalytic　CO2　reduction　is　severely　limited　by　the　rapid　recombination　of　photo-generated　charges　and　insufficient　reactive　sites.　Creating　electric　field　and　defects　are　effective　strategies　to　inhibit　charge　recombination　and　enrich　catalytic　sites,　respectively.　Herein,　a　coupled　strategy　of　ferroelectric　poling　and　cationic　vacancy　is　developed　to　achieve　high-performance　CO2　photoreduction　on　ferroelectric　Bi2MoO6,　and　their　interesting　synergy-compensation　relationship　is　first　disclosed.　Corona　poling　increases　the　remnant　polarization　of　Bi2MoO6　to　enhance　the　intrinsic　electric　field　for　promoting　charge　separation,　while　it　decreases　the　CO2　adsorption.　The　introduced　Mo　vacancy　(V-Mo)　facilitates　the　adsorption　and　activation　of　CO2,　and　surface　charge　separation　by　creating　local　electric　field.　Unfortunately,　V-Mo　largely　reduces　the　remnant　polarization　intensity.　Coupling　poling　and　V-Mo　not　only　integrate　their　advantages,　resulting　in　an　approximately　sevenfold　increased　surface　charge　transfer　efficiency,　but　also　compensate　for　their　shortcomings,　for　example,　V-Mo　largely　alleviates　the　negative　effects　of　ferroelectric　poling　on　CO2　adsorption.　In　the　absence　of　co-catalyst　or　sacrificial　agent,　the　poled　Bi2MoO6　with　V-Mo　exhibits　a　superior　CO2-to-CO　evolution　rate　of　19.75　mu　mol　g(-1)　h(-1),　approximate　to　8.4　times　higher　than　the　Bi2MoO6　nanosheets.　This　work　provides　new　ideas　for　exploring　the　role　of　polarization　and　defects　in　photocatalysis.