Vibrations　are　usually　harmful　in　engineering　and　thus　need　to　be　mitigated,　whereas　they　are　also　potential　sources　of　useful　energy　and　can　be　harnessed.　Current　difficulty　in　vibration　mitigation　and　energy　harvesting　is　to　achieve　both　objectives　synchronously,　especially　in　low-frequency　environments.　In　this　paper,　a　device　composed　of　quasi-zero-stiffness　(QZS)　pneumatic　support　and　magnetic-piezoelectric　cantilever　beams　is　proposed　for　synchronous　low-frequency　vibration　mitigation　and　energy　harvesting.　The　pneumatic　support　enables　the　adaptability　to　different　load　masses　while　maintaining　QZS.　The　magnetic　spacing　in　the　magnetic-piezoelectric　cantilever　beam　can　be　adjusted　to　produce　various　stiffness　properties,　including　nonlinear　positive　stiffness,　QZS,　and　bistability.　The　nonlinear　dynamic　behaviors　are　studied　and　the　performances　are　analyzed　based　on　the　electromechanical　coupled　equations.　Results　indicate　that　energy　harvesting　and　vibration　mitigation　can　be　achieved　at　low　frequencies,　and　most　importantly　the　energy　harvesting　region　is　located　within　the　vibration　mitigation　region,　implying　synchronization　of　the　two　objectives.　Different　situations　induced　by　the　bifurcation　of　magnetic　spacing　are　studied　and　discussed.　It　is　shown　that　the　magnetic　spacing　that　produces　QZS　for　the　cantilever　beam　is　the　best　choice,　and　the　energy　harvesting　region　can　be　easily　tuned　by　adjusting　the　magnetic　spacing.　©　2024