With　the　development　of　integrated　circuits,　the　volume　and　power　consumption　of　electrical　equipment　have　decreased　dramatically.　As　an　excellent　energy　conversion　method,　piezoelectric　energy　harvester　can　capture　the　vibration　energy　of　the　environment,　so　as　to　realize　the　self-powered　supply　of　micro　and　small　power　electronic　devices.　In　this　paper,　a　variable　cross-section　extended　beam　structure　is　considered　as　the　structure　form　of　piezoelectric　energy　harvester.　The　influence　of　structural　parameters　on　the　steady-state　response　of　piezoelectric　energy　harvester　is　analyzed,　which　can　improve　the　output　voltage　and　collection　efficiency　of　the　energy　harvester.　The　results　show　that　the　thickness　of　the　beam　has　a　great　influence　on　the　natural　frequency　of　the　piezoelectric　energy　harvester　system,　but　has　little　influence　on　the　output　response.　By　changing　the　thickness　of　the　beam,　the　low-frequency　energy　can　be　captured　and　the　energy　collection　efficiency　can　be　improved.　The　thickness　of　the　beam　piezoelectric　layer　has　a　great　influence　on　the　natural　frequency　of　the　piezoelectric　energy　harvester　system,　but　has　little　influence　on　the　output　response.　By　reducing　the　thickness　of　piezoelectric　layer,　the　efficiency　of　energy　collection　can　be　improved.