In　this　study,　a　high　quality　Na0.52K0.435Li0.045Nb0.905Ta0.05Sb0.045O3　(LS45-H)　ceramic　has　been　prepared　from　mechanochemically　activated　LS45　powder　and　normal　sintering　in　air,　which　is　promising　for　use　in　lead-free　piezoelectric　energy　harvester.　Herein,　the　LS45-H　ceramic　not　only　has　less　defect　structure,　but　also　has　a　more　uniform　and　denser　microstructure.　Furthermore,　the　LS45-H　ceramic　exhibits　excellent　energy　harvesting　performance　in　the　mode　of　cantilever-type　structure,　and　a　high　output　power　of　11.5　mu　W　and　output　voltage　of　5　V　were　obtained　at　the　acceleration　of　10　m/s(2).　This　work　provides　a　simple　method　for　preparing　dense,　uniform　KNN　ceramics　without　abnormal　grain　growth,　and　we　believed　that　the　LS45-H　ceramic　has　a　potential　application　in　piezoelectric　energy　harvester　for　self-powered　sources　of　wireless　sensor　network　systems.