The present disclosure provides an acoustic device, including a frame, a vibration system fixed to the frame, a magnetic circuit system configured to drive the vibration system to vibrate and produce a sound, and a magnetic frame sealing cap configured to fix the magnetic circuit system to the frame, where the magnetic circuit system includes a magnetic yoke and a magnet fixed to the magnetic yoke, the magnetic frame sealing cap includes a bottom wall and a side wall that is in a ring shape and is bent and extends from a periphery of the bottom wall, the magnetic yoke is fixed to the bottom wall, and the side wall is fixed to the frame. Compared with the related art, the acoustic performance of the acoustic device of the present disclosure is optimal.