The invention discloses a bent actuator-based thin-walled workpiece machining vibration suppressing device. The vibration suppressing device comprises a vibration detection unit, a signal acquisitionunit, a power amplification unit, a control computer, a programmable signal generator and a bent actuator; the bent actuator is used for applying a reverse vibration suppressing force to a thin-walledworkpiece to perform active control over regenerative chatter vibration in a milling process. The invention further discloses an active vibration control method aiming at the vibration suppressing device. The vibration suppressing device disclosed by the invention is capable of realizing real-time detection and feedback control on the vibration of the thin-walled workpiece in the milling processby relatively high precision, is fast in response speed, has a big and accurate output force, also has the advantages of being small in size, low in power consumption, high unit volume strain energy,and the like, and can adapt to the narrow machining space of a thin-walled workpiece complicated in shape and the complexity and the time variation of the dynamic characteristic of a tool-workpiece system in the machining process of the thin-walled workpiece complicated in shape.