The　pursuit　of　high-performance　piezo-photocatalysts　through　structural　modifications　has　been　a　focal　point　of　investigation　within　the　realm　of　related　scientific　disciplines.　In　this　study,　we　successfully　designed　Er　-doped　Bi　0.5　Na　0.5　TiO　3　-BaTiO　3　combined　with　rare　earth　ion　doping　and　solid　solution　modification,　and　the　prepared　particles　exhibited　homogeneous　grain　sizes　and　optimized　concentrations　of　oxygen　vacancies　(O　V　).　The　synergistic　incorporation　of　O　V　(accelerator　for　catalytic　reaction)　and　Er　3　+　results　in　an　impressive　12　-fold　enhancement　of　the　piezo-photocatalytic　rate　when　degrading　the　Rhodamine　B　dye.　The　optimal　composition　0.96BNT-0.04BT-Er　demonstrates　outstanding　electrochemical　properties,　including　a　superior　photocurrent　response　and　minimal　impedance,　highlighting　its　exceptional　performance　in　piezo-photocatalysis.　The　fundamental　enhancement　in　catalytic　performance　can　be　attributed　to　the　reconfiguration　of　the　band　structure　of　0.96BNT-0.04BT-Er,　which　has　been　meticulously　calculated　utilizing　DRS　and　VB-XPS　and　the　internal　mechanism　was　explained　in　detail.　This　research　serves　as　a　source　of　inspiration　for　the　investigation　of　solid　solutions　among　piezo-photocatalysts　and　sheds　light　on　the　vital　role　of　band　structure　in　governing　catalytic　performance.