Piezocatalysis,　governed　by　piezo-potential　within　piezoelectrics,　has　gained　prominence　for　reactive　oxygen　species　(ROS)　generation,　which　is　significant　to　environmental　and　biological　applications.　However,　designing　piezocatalysts　with　excellent　piezocatalytic　performance　in　a　wide　temperature　and　efficient　charge　carrier　separation　ability　is　still　challenging.　Herein,　eco-friendly　BaTiO3　(BT)-based　perovskite　ferroelectrics　with　tailored　multiphase　coexistence　in　a　wide　temperature　range　are　constructed　to　boost　higher　piezoelectricity　and　large　piezo-potential,　which　is　attributed　to　decreased　polarization　anisotropy　by　flat　Gibbs　energy　profile.　Elevated　piezo-potential　in　designed　BT-based　piezocatalyst　guarantees　high-efficient　generation　rate　of　•OH　(200 µmol g−1 h−1)　and　•O2−　(40 µmol g−1 h−1)　by　ultrasound　stimulation,　which　is　3.5　times　more　than　that　of　pure　BT.　Besides,　piezocatalytic　capacity　to　degrade　dye　wastewater　shows　a　rate　constant　of　0.0182 min−1　and　gives　an　antibacterial　rate　of　95%　within　30 min　for　eliminating　E.　coli.　Theoretical　simulations　validate　that　the　local　distortion　of　TiO6　octahedra　also　contributes　to　piezocatalytic　performance　by　inducing　electron–hole　pairs　separation　in　real　space,　and　better　response　to　slight　structural　deformation.　This　work　is　important　to　design　high-performance　piezocatalysts　with　high-efficiency　ROS　generation　for　sewage　treatment　and　sonodynamic　therapy.　©　2023　Wiley-VCH　GmbH.