The　transformation　of　waste　vibration　energy　into　low-power　electricity　has　been　intensely　researched　over　the　last　decade　to　enable　self-sustained　wireless　electronic　components.　Many　kinds　of　nonlinear　oscillators　have　been　explored　by　several　research　groups　in　an　effort　to　enhance　the　frequency　bandwidth　of　operation.　The　negative　stiffness　vibration　isolator,　as　a　kind　of　passive　vibration　isolator,　has　undergone　extensive　investigation　because　of　its　low-frequency　isolator　characteristics.　In　this　article,　a　novel　broadband　piezoelectric　vibration　energy　harvester,　which　can　be　used　for　low-frequency　ambient　mechanical　energy　harvesting,　is　designed,　and　its　dynamic　responses　are　analyzed　based　on　the　advantage　of　the　negative　stiffness　vibration　isolator.　The　multi-scale　perturbation　method　is　applied　to　solve　the　electromechanical　equations　of　the　piezoelectric　vibration　energy　harvester　and　obtain　approximate　analytical　solutions.　Solutions　based　on　the　analytical　method　and　numerical　simulations　reveal　the　characteristics　of　significant　broadband　performance.　The　effects　of　the　various　system　parameters　on　the　frequency　responses　and　output　voltage　of　the　piezoelectric　vibration　energy　harvester　system　are　investigated　in　detail,　and　the　vibration　isolation　ability　is　verified　by　experimental　measurements.　It　was　concluded　that　the　proposed　piezoelectric　vibration　energy　harvester　achieved　broadband　vibration　energy　harvesting　in　the　low-frequency　vibration　range.