Developing　efficient　piezocatalytic　systems　for　two-electron　water　splitting　(TEWS)　with　producing　H-2　and　H2O2　shows　great　promise　to　meet　the　industrial　demand.　Herein,　Ag　single　atoms　(SAs)　and　clusters　are　co-anchored　on　carbon　nitride　(AgSA+C-CN)　to　serve　as　the　multifunctional　sites　for　efficient　TEWS.　The　Ag　SAs　enhance　the　in-plane　piezoelectric　polarization　of　CN　that　is　intimately　modulated　by　the　atomic　coordination　induced　charge　redistribution,　and　Ag　clusters　afford　strong　interfacial　electric　field　to　remarkably　promote　the　out-of-plane　migration　of　piezoelectrons　from　CN.　Moreover,　AgSA+C-CN　yields　a　larger　piezoresistive　effect　that　elevates　carrier　mobility　under　strain.　Consequently,　a　superior　H-2　and　H2O2　evolution　rate　of　7.90　mmol　g(-1)　h(-1)　and　5.84　mmol　g(-1)　h(-1)　is　delivered　by　AgSA+C-CN,　respectively,　far　exceeding　that　of　the　previously　reported　piezocatalysts.　This　work　not　only　presents　the　SAs　decoration　as　an　available　polarization　enhancement　strategy,　but　also　sheds　light　on　the　superiority　of　multi-sites　engineering　in　piezocatalysis.