In-depth　exploration　of　the　local　surface　plasmon　resonance　and　piezoelectric　effects　associated　with　metal　can　help　develop　efficient　biosensors.　Here,　we　presented　for　the　first　time　the　localized　surface　plasmon　resonance　(LSPR)　and　piezoelectric　effects　co-enhance　the　construction　of　an　efficient　intra-body　phase　electric　field　for　the　construction　of　efficient　photoelectrochemical　(PEC)　biosensors.　Briefly,　the　LSPR　enhancement　and　piezoelectric　enhancement　effects　between　Ag　nanoparticles　and　the　piezoelectric　material　NaNbO3　were　investigated　in　a　PEC　biosensor　system　under　the　excitation　of　portable　UV　light.　Notably,　the　simplified　treatment　of　the　basic　building　blocks　of　the　PEC　sensor,　including　a　handheld　UV　flashlight　instead　of　a　physical　excitation　light　source　and　a　digital　multimeter　instead　of　an　electrochemical　workstation.　The　capture　and　immunoincubation　process　of　target　PSA　occurs　on　separated　microtiter　plates　and　hydrogen　peroxide,　generated　by　enzyme-linked　immunization,　induces　the　directional　separation　of　electrons　and　holes　in　the　composite　heterogeneous　material　under　the　excitation　of　light.　The　coupling　with　a　digital　multimeter　allows　for　real-time　monitoring　of　photocurrents.　Further,　the　effect　of　Ag　deposition　on　piezoelectric　perovskite　NaNbO3　was　obtained　by　density　functional　theory　(DFT)　calculations.　Impressively,　under　optimized　conditions,　the　system　exhibits　an　ultra-wide　linear　range　and　ultra-low　detection　limits　for　the　target　PSA.　The　system　is　also　comparable　to　commercially　available　ELISA　kits　at　the　95%　confidence　level.　This　work　provides　a　novel　idea　of　enhanced　PEC　biosensor　for　rapid　and　accurate　detection　of　cancer-related　proteins.　©　2022