A novel circular piezoelectric bone-conduction hearing device with a leaf spring support was proposed to improve its lower-frequency response performance. The equivalent dynamic system containing a support spring and a piezoelectric vibrator was analyzed theoretically by building the dynamic-model of the hearing device. The structure of the support spring was designed after selecting an optimum spring with the thickness of 0.9 mm as the support element. A prototype of piezoelectric bone-conduction hearing device was developed and the test system was built. The experimental test on amplitude-frequency characteristics and loudness-frequency characteristics were conducted. The results show that the maximum response amplitude of the piezoelectric system has reached up to 22.21 μm at 550 Hz. Furthermore, the loudness of the hearing device is between 60 dB and 70 dB in the low-frequency region, and that is stabilized at about 80 dB in the high-frequency region.The noise of the device is within a basically reasonable level of 35-40 dB at one meter away.It concludes that the response amplitude of the hearing device is larger in the low-frequency region; the loudness of the device basically meets the requirements of the wearers with a smaller noise.