The　electrocatalytic　conversion　of　inert　CO2　to　value-added　chemical　fuels　powered　by　renewable　energy　is　one　of　the　benchmark　approaches　to　address　excessive　carbon　emissions　and　achieve　carbon-neutral　energy　restructuring.　However,　the　adsorption/activation　of　supersymmetric　CO2　is　facing　insurmountable　challenges　that　constrain　its　industrial-scale　applications.　Here,　this　theory-guided　study　confronts　these　challenges　by　leveraging　the　synergies　of　bimetallic　sites　and　defect　engineering,　where　pyrochlore-type　semiconductor　A(2)B(2)O(7)　is　employed　as　research　platform　and　the　conversion　of　CO2-to-HCOOH　as　the　model　reaction.　Specifically,　defect　engineering　intensified　greatly　the　chemisorption-induced　CO2　polarization　via　the　bimetallic　coordination,　thermodynamically　beneficial　to　the　HCOOH　production　via　the　*HCO2　intermediate.　The　optimal　V-BSO-430　electrocatalyst　with　abundant　surface　oxygen　vacancies　achieved　a　superior　HCOOH　yield　of　116.7　mmol　h(-1)　cm(-2)　at　-1.2　V-RHE,　rivalling　the　incumbent　similar　reaction　systems.　Furthermore,　the　unique　catalytic　unit　featured　with　a　Bi-1-Sn-Bi-2　triangular　structure,　which　is　reconstructed　by　defect　engineering,　and　altered　the　pathway　of　CO2　adsorption　and　activation　to　allow　the　preferential　affinity　of　the　suspended　O　atom　in　*HCO2　to　H.　As　a　result,　V-BSO-430　gave　an　impressive　FEHCOOH　of　93%　at　-1.0　V-RHE.　This　study　held　promises　for　inspiring　the　exploration　of　bimetallic　materials　from　the　massive　semiconductor　database.