Vibration　energy　harvesting　is　to　transform　the　ambient　mechanical　energy　to　electricity.　How　to　reduce　the　resonance　frequency　and　improve　the　conversion　efficiency　is　very　important.　In　this　paper,　a　layer-separated　piezoelectric　cantilever　beam　is　proposed　for　the　vibration　energy　harvester　(VEH)　for　low-frequency　and　wide-bandwidth　operation,　which　can　transform　the　mechanical　impact　energy　to　electric　energy.　First,　the　electromechanical　coupling　equation　is　obtained　by　the　Euler-Bernoulli　beam　theory.　Based　on　the　average　method,　the　approximate　analytical　solution　is　derived　and　the　voltage　response　is　obtained.　Furthermore,　the　physical　prototype　is　fabricated,　and　the　vibration　experiment　is　conducted　to　validate　the　theoretical　principle.　The　experimental　results　show　that　the　maximum　power　of　0.445　W　of　the　layer-separated　VEH　is　about　3.11　times　higher　than　that　of　the　non-impact　harvester　when　the　excitation　acceleration　is　0.2　g.　The　operating　frequency　bandwidth　can　be　widened　by　increasing　the　stiffness　of　the　fundamental　layer　and　decreasing　the　gap　distance　of　the　system.　But　the　increasing　of　operating　frequency　bandwidth　comes　at　the　cost　of　reducing　peak　voltage.　The　theoretical　simulation　and　the　experimental　results　demonstrate　good　agreement　which　indicates　that　the　proposed　impact-driving　VEH　device　has　advantages　for　low-frequency　and　wide-bandwidth.　The　high　performance　provides　great　prospect　to　scavenge　the　vibration　energy　in　environment.